fix(skillopt): emit proposed.md in no-mutate mode (#2635)

writeProposed now writes both best.md (optimizer's current-best pointer)
and proposed.md (the stable review artifact documented by --no-mutate);
the orchestrator returns the real proposed.md path instead of aliasing
best.md. Fix lands in the shared helper so both accept-branch call sites
are covered.

Takeover of #2719.

Co-authored-by: RerankerGuo <RerankerGuo@users.noreply.github.com>
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/tutorials/improving-skills-with-skillopt.md

@@ -233,13 +233,14 @@ keep it or `git checkout` to throw it away. Nothing is committed for you.
 
 **For a skill that ships with gbrain** (anything under the gbrain repo's own
 `skills/`): SkillOpt refuses to overwrite it by default and writes the winner to
-`skills/<name>/skillopt/best.md` instead, so an optimization pass can never
-silently mutate a skill other people depend on. Two ways to handle that:
+`skills/<name>/skillopt/proposed.md` instead (while keeping `best.md` as the
+optimizer's current-best pointer), so an optimization pass can never silently
+mutate a skill other people depend on. Two ways to handle that:
 
 ```bash
 # See the proposed improvement without touching SKILL.md (works for ANY skill):
 gbrain skillopt meeting-prep --split 1:1:1 --no-mutate
-# → writes skills/meeting-prep/skillopt/best.md (the proposed rewrite), prints its path. Copy what you want.
+# → writes skills/meeting-prep/skillopt/proposed.md, updates best.md, and prints the proposal path.
 
 # Actually rewrite a bundled skill (explicit opt-in + an independent held-out set):
 gbrain skillopt brain-ops --split 1:1:1 --allow-mutate-bundled \

src/commands/embed.ts

@@ -1,7 +1,6 @@
 import type { BrainEngine } from '../core/engine.ts';
 import { embedBatch, currentEmbeddingSignature } from '../core/embedding.ts';
-import type { ChunkInput, ResolvedColumn } from '../core/types.ts';
-import { resolveWriteColumnForEngine } from '../core/search/embedding-column.ts';
+import type { ChunkInput } from '../core/types.ts';
 import { chunkText } from '../core/chunkers/recursive.ts';
 import { createProgress, type ProgressReporter } from '../core/progress.ts';
 import { getCliOptions, cliOptsToProgressOptions } from '../core/cli-options.ts';
@@ -184,13 +183,8 @@ export class EmbeddingDimMismatchError extends Error {
  * fresh-install bug class at the very first invocation instead of letting
  * the worker pool hammer N pages with raw 22000 errors.
  */
-async function preflightDimMismatch(engine: BrainEngine, dryRun: boolean, embeddingColumn?: ResolvedColumn): Promise<void> {
+async function preflightDimMismatch(engine: BrainEngine, dryRun: boolean): Promise<void> {
   if (dryRun) return; // dry-run never embeds, no risk
-  // #1262: an alt-column brain writes to `embeddingColumn`, not the legacy
-  // `embedding` column — the legacy column's dims are irrelevant, and the
-  // registry entry (validated at resolve time) pins the target's dims. Only
-  // the legacy default path needs the schema-vs-gateway dim comparison.
-  if (embeddingColumn && embeddingColumn.name !== 'embedding') return;
   const { readContentChunksEmbeddingDim, embeddingMismatchMessage } = await import('../core/embedding-dim-check.ts');
   const { getEmbeddingDimensions, getEmbeddingModel } = await import('../core/ai/gateway.ts');
   let existing;
@@ -244,12 +238,7 @@ export async function runEmbedCore(engine: BrainEngine, opts: EmbedOpts): Promis
   // v0.37.11.0 (Lane D.2): pre-flight dim-mismatch check. Catches the headline
   // fresh-install bug class before the worker pool spends 20 parallel calls
   // hitting raw Postgres dimension errors.
-  // #1262: resolve the write-side embedding column ONCE at the boundary
-  // (merged config + gateway model) and thread the descriptor through every
-  // upsertChunks / stale-scan below. undefined => legacy `embedding` column.
-  const embeddingColumn = await resolveWriteColumnForEngine(engine);
-
-  await preflightDimMismatch(engine, !!opts.dryRun, embeddingColumn);
+  await preflightDimMismatch(engine, !!opts.dryRun);
 
   const result: EmbedResult = {
     embedded: 0,
@@ -264,7 +253,7 @@ export async function runEmbedCore(engine: BrainEngine, opts: EmbedOpts): Promis
     for (const s of opts.slugs) {
       if (isAborted(opts.signal)) break; // #1737: stop the per-slug loop on abort
       try {
-        await embedPage(engine, s, !!opts.dryRun, result, opts.sourceId, opts.signal, embeddingColumn);
+        await embedPage(engine, s, !!opts.dryRun, result, opts.sourceId, opts.signal);
       } catch (e: unknown) {
         serr(`  Error embedding ${s}: ${e instanceof Error ? e.message : e}`);
       }
@@ -358,7 +347,7 @@ export async function runEmbedCore(engine: BrainEngine, opts: EmbedOpts): Promis
         catchUp: opts.catchUp,
         pacer,
         paceMaxConcurrency,
-      }, opts.signal, embeddingColumn);
+      }, opts.signal);
     } finally {
       // E1: surface pacing telemetry (human + structured) when pacing was on.
       const snap = pacer.snapshot();
@@ -387,7 +376,7 @@ export async function runEmbedCore(engine: BrainEngine, opts: EmbedOpts): Promis
     return result;
   }
   if (opts.slug) {
-    await embedPage(engine, opts.slug, !!opts.dryRun, result, opts.sourceId, opts.signal, embeddingColumn);
+    await embedPage(engine, opts.slug, !!opts.dryRun, result, opts.sourceId, opts.signal);
     return result;
   }
   throw new Error('No embed target specified. Pass { slug }, { slugs }, { all }, or { stale }.');
@@ -532,13 +521,8 @@ async function embedPage(
   result: EmbedResult,
   sourceId?: string,
   signal?: AbortSignal,
-  embeddingColumn?: ResolvedColumn,
 ) {
   const opts = sourceId ? { sourceId } : undefined;
-  // #1262: write-side descriptor rides only on WRITE calls (upsertChunks).
-  const chunkOpts = (sourceId || embeddingColumn)
-    ? { ...(sourceId && { sourceId }), ...(embeddingColumn && { embeddingColumn }) }
-    : undefined;
   const page = await engine.getPage(slug, opts);
   if (!page) {
     throw new Error(`Page not found: ${slug}`);
@@ -570,7 +554,7 @@ async function embedPage(
     }
 
     if (inputs.length > 0) {
-      await engine.upsertChunks(slug, inputs, chunkOpts);
+      await engine.upsertChunks(slug, inputs, opts);
       chunks = await engine.getChunks(slug, opts);
     }
   }
@@ -605,7 +589,7 @@ async function embedPage(
     token_count: c.token_count || Math.ceil(c.chunk_text.length / 4),
   }));
 
-  await engine.upsertChunks(slug, updated, chunkOpts);
+  await engine.upsertChunks(slug, updated, opts);
   // v0.41.31: stamp provenance so a later model/dims swap is detectable as
   // stale. embedPage is the per-slug path used by `gbrain embed <slug>` AND
   // by `gbrain sync`'s post-import embed step (runEmbedCore({slugs})).
@@ -638,7 +622,6 @@ async function embedAll(
     paceMaxConcurrency?: number;
   },
   signal?: AbortSignal,
-  embeddingColumn?: ResolvedColumn,
 ) {
   // v0.41.31: current embedding provenance signature. Stamped onto pages
   // when their chunks are (re)embedded so a later model/dimension swap is
@@ -661,7 +644,7 @@ async function embedAll(
     // D7: thread sourceId so `gbrain embed --stale --source X` actually scopes.
     // v0.41.18.0 (A13): thread batchSize/priority/catchUp into the stale path.
     // #1737: thread the external abort signal so the cycle embed phase bails.
-    return await embedAllStale(engine, sourceId, dryRun, result, onProgress, staleOpts, signature, signal, embeddingColumn);
+    return await embedAllStale(engine, sourceId, dryRun, result, onProgress, staleOpts, signature, signal);
   }
 
   // --all path: pacer (no-op when off). E-1: lower the worker count to the
@@ -742,10 +725,7 @@ async function embedAll(
         embedding: embeddingMap.get(c.chunk_index) ?? undefined,
         token_count: c.token_count || Math.ceil(c.chunk_text.length / 4),
       }));
-      await observed(pacer, () => engine.upsertChunks(page.slug, updated, {
-        ...(pageSourceId && { sourceId: pageSourceId }),
-        ...(embeddingColumn && { embeddingColumn }),
-      }));
+      await observed(pacer, () => engine.upsertChunks(page.slug, updated, pageOpts));
       // v0.41.31: stamp embedding provenance so a later model swap is
       // detectable as stale.
       await observed(pacer, () =>
@@ -825,16 +805,10 @@ async function embedAllStale(
   },
   signature?: string,
   externalSignal?: AbortSignal,
-  embeddingColumn?: ResolvedColumn,
 ) {
   // D7: thread sourceId so source-scoped runs only count + visit
   // that source's NULL embeddings.
-  // #1262: the stale predicate follows the write-side column — without it an
-  // alt-column brain would perpetually re-select (and re-pay for) chunks whose
-  // target column is already populated.
-  const sourceOpt = (sourceId || embeddingColumn)
-    ? { ...(sourceId && { sourceId }), ...(embeddingColumn && { embeddingColumn }) }
-    : undefined;
+  const sourceOpt = sourceId ? { sourceId } : undefined;
 
   // v0.41.31: re-embed pages whose embedding_signature drifted (model/dims
   // swap). dry-run must NOT mutate, so it counts signature-stale via the
@@ -993,7 +967,6 @@ async function embedAllStale(
             afterUpdatedAt,
           }),
           ...(sourceId && { sourceId }),
-          ...(embeddingColumn && { embeddingColumn }),
         }),
       );
       if (batch.length === 0) {
@@ -1046,10 +1019,7 @@ async function embedAllStale(
             embedding: staleIdxToEmbedding.get(c.chunk_index) ?? undefined,
             token_count: c.token_count || Math.ceil(c.chunk_text.length / 4),
           }));
-          await observed(pacer, () => engine.upsertChunks(slug, merged, {
-            sourceId: keySourceId,
-            ...(embeddingColumn && { embeddingColumn }),
-          }));
+          await observed(pacer, () => engine.upsertChunks(slug, merged, { sourceId: keySourceId }));
           // v0.41.31: stamp provenance after the page's chunks are embedded —
           // but only when EVERY chunk was stale (fully re-embedded this pass).
           // A partially-stale page keeps preserved chunks of unknown/old
@@ -1120,7 +1090,7 @@ async function embedAllStale(
   // as a clean run — re-running won't help until the underlying failure is fixed.
   if (staleOpts?.catchUp && !effectiveSignal.aborted && embedFailures > 0) {
     const remaining = await engine.countStaleChunks(
-      signature ? { signature, ...sourceOpt } : sourceOpt,
+      signature ? { signature, ...(sourceId ? { sourceId } : {}) } : (sourceId ? { sourceId } : undefined),
     );
     if (remaining > 0) {
       serr(`\n  [embed] catch-up finished but ${remaining} chunk(s) remain stale after ${embedFailures} embed failure(s). These are not embeddable as-is; re-running won't clear them until the underlying error is resolved.`);

src/commands/sync.ts

@@ -576,16 +576,9 @@ async function runInlineCostGate(
 
   // Stale backlog: cheap single SQL; fail-open to 0 so a transient DB hiccup
   // never blocks the sync. Signature-aware (model/dims swap surfaces here).
-  // #1262: follow the write-side embedding column — otherwise an alt-column
-  // brain's fully-embedded corpus counts as phantom backlog on every gate.
   let staleChars = 0;
   try {
-    const { resolveWriteColumnForEngine } = await import('../core/search/embedding-column.ts');
-    const embeddingColumn = await resolveWriteColumnForEngine(engine);
-    staleChars = await engine.sumStaleChunkChars({
-      signature: currentEmbeddingSignature(),
-      ...(embeddingColumn && { embeddingColumn }),
-    });
+    staleChars = await engine.sumStaleChunkChars({ signature: currentEmbeddingSignature() });
   } catch {
     staleChars = 0;
   }

src/core/contextual-retrieval-service.ts

@@ -61,7 +61,6 @@ import {
   type SynopsisFailureKind,
 } from './audit-synopsis.ts';
 import type { BrainEngine } from './engine.ts';
-import { resolveWriteColumnForEngine } from './search/embedding-column.ts';
 import type { ChunkInput, CRMode, Page } from './types.ts';
 import type { SourceRow } from './sources-ops.ts';
 
@@ -287,13 +286,9 @@ export async function reembedPageWithContextualRetrieval(
 
       // ── PHASE 2: single DB transaction ───────────────────────────
       try {
-        // #1262: contextual re-embeds write TEXT embeddings — thread the
-        // caller-resolved write column like every other embed path.
-        const embeddingColumn = await resolveWriteColumnForEngine(args.engine);
         await args.engine.transaction(async (tx) => {
           await tx.upsertChunks(args.pageSlug, phase1.embeddedChunks, {
             sourceId: args.sourceId,
-            ...(embeddingColumn && { embeddingColumn }),
           });
           await tx.updatePageContextualRetrievalState(
             args.pageSlug,

src/core/embed-stale.ts

@@ -18,7 +18,7 @@
  */
 
 import type { BrainEngine } from './engine.ts';
-import type { ChunkInput, ResolvedColumn } from './types.ts';
+import type { ChunkInput } from './types.ts';
 import { embedBatchWithBackoff } from '../commands/embed.ts';
 import { type DbPacer, createNoopPacer, observed } from './db-pacer.ts';
 import { AbortError } from './abort-check.ts';
@@ -61,13 +61,6 @@ export interface EmbedStaleOpts {
    * Omit to keep the legacy `embedding IS NULL`-only behavior.
    */
   embeddingSignature?: string;
-  /**
-   * #1262: caller-resolved write-side embedding column. Threaded into BOTH
-   * listStaleChunks (staleness predicate) and upsertChunks (write target) so
-   * an alt-column brain converges instead of re-selecting embedded rows.
-   * Resolve at the boundary via `resolveWriteColumnForEngine()`.
-   */
-  embeddingColumn?: ResolvedColumn;
   /**
    * DB-contention pacer (paced-backfill). When enabled it (a) supplies the
    * worker count via the caller passing `concurrency = bundle.maxConcurrency`
@@ -163,7 +156,6 @@ export async function embedStaleForSource(
         afterPageId,
         afterChunkIndex,
         sourceId,
-        ...(opts.embeddingColumn && { embeddingColumn: opts.embeddingColumn }),
       }),
     );
     if (batch.length === 0) {
@@ -231,10 +223,7 @@ export async function embedStaleForSource(
           doc_comment: c.doc_comment ?? undefined,
           symbol_name_qualified: c.symbol_name_qualified ?? undefined,
         }));
-        await observed(pacer, () => engine.upsertChunks(slug, merged, {
-          sourceId: keySourceId,
-          ...(opts.embeddingColumn && { embeddingColumn: opts.embeddingColumn }),
-        }));
+        await observed(pacer, () => engine.upsertChunks(slug, merged, { sourceId: keySourceId }));
         // v0.41.31: stamp provenance only when EVERY chunk was stale (fully
         // re-embedded this pass) — a partially-stale page keeps preserved
         // chunks of unknown provenance, so don't claim current. After the

src/core/engine.ts

@@ -12,7 +12,6 @@ import type {
   BrainStats, BrainHealth,
   IngestLogEntry, IngestLogInput,
   EngineConfig,
-  ResolvedColumn,
   CodeEdgeInput, CodeEdgeResult,
   EvalCandidate, EvalCandidateInput,
   EvalCaptureFailure, EvalCaptureFailureReason,
@@ -988,13 +987,8 @@ export interface BrainEngine {
    * — Postgres rolls back automatically on conn drop, so commit-ambiguous
    * failure replays to the same end state. Callers MUST NOT wrap externally;
    * see {@link BatchOpts} retry-contract block.
-   *
-   * `opts.embeddingColumn` (optional) selects the content_chunks column that
-   * receives TEXT embeddings (#1262). The caller resolves the descriptor at
-   * the import/embed boundary via `resolveWriteColumn()`; engines never read
-   * config or choose columns themselves. Omitted => legacy `embedding`.
    */
-  upsertChunks(slug: string, chunks: ChunkInput[], opts?: { sourceId?: string; embeddingColumn?: ResolvedColumn } & BatchOpts): Promise<void>;
+  upsertChunks(slug: string, chunks: ChunkInput[], opts?: { sourceId?: string } & BatchOpts): Promise<void>;
   /**
    * Read every chunk for a page. `opts.sourceId` source-scopes the page
    * lookup; without it, multi-source brains return chunks from every
@@ -1011,13 +1005,8 @@ export interface BrainEngine {
    * counts across every source in the brain. Operators running
    * `gbrain embed --stale --source media-corpus` expect only that
    * source's NULLs touched; the caller threads `sourceId` here.
-   *
-   * `opts.embeddingColumn` switches the staleness predicate from the legacy
-   * `embedding` column to the resolved write-side column, so alt-column
-   * brains do not perpetually re-select rows whose target column is already
-   * populated (#1262). Must match the eventual upsertChunks target.
    */
-  countStaleChunks(opts?: { sourceId?: string; signature?: string; embeddingColumn?: ResolvedColumn }): Promise<number>;
+  countStaleChunks(opts?: { sourceId?: string; signature?: string }): Promise<number>;
   /**
    * Sum of LENGTH(chunk_text) over stale chunks — the character-count
    * backlog the embed phase / embed-backfill will process. Sibling of
@@ -1031,13 +1020,8 @@ export interface BrainEngine {
    * model signature (a model/dims swap). NULL signature is GRANDFATHERED
    * (never counted) so the post-migration corpus isn't flagged en masse.
    * Omit `signature` for the legacy `embedding IS NULL`-only count.
-   *
-   * `opts.embeddingColumn` switches the staleness predicate to the resolved
-   * write-side column (#1262) — same contract as countStaleChunks — so the
-   * sync cost gate doesn't count an alt-column brain's fully-embedded corpus
-   * as phantom backlog.
    */
-  sumStaleChunkChars(opts?: { sourceId?: string; signature?: string; embeddingColumn?: ResolvedColumn }): Promise<number>;
+  sumStaleChunkChars(opts?: { sourceId?: string; signature?: string }): Promise<number>;
   /**
    * Stamp `pages.embedding_signature = signature` for one page. Called after
    * a page's chunks are (re)embedded so a later model swap can detect it as
@@ -1085,9 +1069,6 @@ export interface BrainEngine {
     // both round-trip TIMESTAMPTZ as Date | string; ISO string is the
     // common denominator on the wire).
     afterUpdatedAt?: string | null;
-    // #1262: staleness predicate targets this column when set (must match
-    // countStaleChunks and the eventual upsertChunks write target).
-    embeddingColumn?: ResolvedColumn;
   }): Promise<StaleChunkRow[]>;
   /**
    * Delete every chunk for a page. Internal page-id lookup is sourceId-scoped

src/core/import-file.ts

@@ -10,8 +10,7 @@ import { findChunkForOffset } from './chunkers/edge-extractor.ts';
 import { extractCodeRefs, imageOfCandidates } from './link-extraction.ts';
 import { embedBatch, embedMultimodal, currentEmbeddingSignature } from './embedding.ts';
 import { slugifyPath, slugifyCodePath, isCodeFilePath } from './sync.ts';
-import type { ChunkInput, PageInput, PageType, ResolvedColumn } from './types.ts';
-import { resolveWriteColumnForEngine } from './search/embedding-column.ts';
+import type { ChunkInput, PageInput, PageType } from './types.ts';
 import { computeEffectiveDate } from './effective-date.ts';
 import { MARKDOWN_CHUNKER_VERSION } from './chunkers/recursive.ts';
 import { logSlugFallback } from './audit-slug-fallback.ts';
@@ -741,14 +740,6 @@ export async function importFromContent(
   // schema DEFAULT — required for multi-source brains; harmless ('default')
   // for single-source callers.
   const txOpts = sourceId ? { sourceId } : undefined;
-  // #1262: resolve the write-side embedding column once (merged config +
-  // gateway model) BEFORE the transaction; the descriptor rides only on
-  // upsertChunks so text embeddings land in the registered column.
-  const chunkWriteColumn = await resolveWriteColumnForEngine(engine);
-  const chunkOpts: { sourceId?: string; embeddingColumn?: ResolvedColumn } | undefined =
-    (sourceId || chunkWriteColumn)
-      ? { ...(sourceId && { sourceId }), ...(chunkWriteColumn && { embeddingColumn: chunkWriteColumn }) }
-      : undefined;
   await engine.transaction(async (tx) => {
     if (existing) await tx.createVersion(slug, txOpts);
 
@@ -833,7 +824,7 @@ export async function importFromContent(
     }
 
     if (chunks.length > 0) {
-      await tx.upsertChunks(slug, chunks, chunkOpts);
+      await tx.upsertChunks(slug, chunks, txOpts);
       // v0.41.31: stamp embedding provenance when this import actually
       // embedded (not --no-embed), so a later model/dims swap is detectable
       // as stale via embed --stale. The deferred/backfill + per-slug embed
@@ -1073,12 +1064,6 @@ export async function importCodeFile(
   const title = `${relativePath} (${lang})`;
   const sourceId = opts.sourceId;
   const txOpts = sourceId ? { sourceId } : undefined;
-  // #1262: write-side embedding column descriptor (rides only on upsertChunks).
-  const chunkWriteColumn = await resolveWriteColumnForEngine(engine);
-  const chunkOpts: { sourceId?: string; embeddingColumn?: ResolvedColumn } | undefined =
-    (sourceId || chunkWriteColumn)
-      ? { ...(sourceId && { sourceId }), ...(chunkWriteColumn && { embeddingColumn: chunkWriteColumn }) }
-      : undefined;
 
   const byteLength = Buffer.byteLength(content, 'utf-8');
   if (byteLength > MAX_FILE_SIZE) {
@@ -1198,7 +1183,7 @@ export async function importCodeFile(
     await tx.addTag(slug, lang, txOpts);
 
     if (chunks.length > 0) {
-      await tx.upsertChunks(slug, chunks, chunkOpts);
+      await tx.upsertChunks(slug, chunks, txOpts);
       // v0.41.31: stamp embedding provenance ONLY when every chunk was
       // freshly embedded with the current model this call (no reuse-by-hash
       // carrying old-model vectors). Mixed pages stay unstamped rather than
@@ -1347,12 +1332,6 @@ export async function withImportTransaction(
 ): Promise<void> {
   const sourceId = spec.sourceId ?? 'default';
   const txOpts = spec.sourceId ? { sourceId: spec.sourceId } : undefined;
-  // #1262: write-side embedding column descriptor (rides only on upsertChunks).
-  const chunkWriteColumn = await resolveWriteColumnForEngine(engine);
-  const chunkOpts: { sourceId?: string; embeddingColumn?: ResolvedColumn } | undefined =
-    (spec.sourceId || chunkWriteColumn)
-      ? { ...(spec.sourceId && { sourceId: spec.sourceId }), ...(chunkWriteColumn && { embeddingColumn: chunkWriteColumn }) }
-      : undefined;
   await engine.transaction(async (tx) => {
     if (spec.hadExisting) await tx.createVersion(spec.slug, txOpts);
     await tx.putPage(spec.slug, spec.page, txOpts);
@@ -1368,7 +1347,7 @@ export async function withImportTransaction(
     }
     if (spec.chunks !== undefined) {
       if (spec.chunks.length > 0) {
-        await tx.upsertChunks(spec.slug, spec.chunks, chunkOpts);
+        await tx.upsertChunks(spec.slug, spec.chunks, txOpts);
       } else {
         await tx.deleteChunks(spec.slug, txOpts);
       }

src/core/minions/handlers/embed-backfill.ts

@@ -35,7 +35,6 @@ import { tryAcquireDbLock } from '../../db-lock.ts';
 import { BudgetTracker, BudgetExhausted } from '../../budget/budget-tracker.ts';
 import { withBudgetTracker } from '../../ai/gateway.ts';
 import { embedStaleForSource } from '../../embed-stale.ts';
-import { resolveWriteColumnForEngine } from '../../search/embedding-column.ts';
 import { currentEmbeddingSignature } from '../../embedding.ts';
 import { type DbPacer, createDbPacer, createNoopPacer } from '../../db-pacer.ts';
 import { resolvePaceMode, loadPaceModeConfig, readPaceEnv } from '../../pace-mode.ts';
@@ -165,16 +164,12 @@ export function makeEmbedBackfillHandler(engine: BrainEngine) {
     // the supervisor, so pacing it is the headline win.
     const { pacer, concurrency } = await resolveBackfillPacer(engine, job.data);
 
-    // #1262: resolve the write-side embedding column once at the job boundary.
-    const embeddingColumn = await resolveWriteColumnForEngine(engine);
-
     try {
       const result = await withBudgetTracker(tracker, async () =>
         embedStaleForSource(engine, sourceId, {
           batchSize,
           signal: job.signal,
           pacer,
-          ...(embeddingColumn && { embeddingColumn }),
           ...(concurrency !== undefined && { concurrency }),
           // v0.41.31: re-embed pages whose model signature drifted + stamp
           // provenance as chunks land.

src/core/pglite-engine.ts

@@ -40,7 +40,6 @@ import type {
   BrainStats, BrainHealth,
   IngestLogEntry, IngestLogInput,
   EngineConfig,
-  ResolvedColumn,
   EvalCandidate, EvalCandidateInput,
   EvalCaptureFailure, EvalCaptureFailureReason,
   SalienceOpts, SalienceResult, AnomaliesOpts, AnomalyResult,
@@ -2231,20 +2230,12 @@ export class PGLiteEngine implements BrainEngine {
   }
 
   // Chunks
-  async upsertChunks(slug: string, chunks: ChunkInput[], opts?: { sourceId?: string; embeddingColumn?: ResolvedColumn } & BatchOpts): Promise<void> {
+  async upsertChunks(slug: string, chunks: ChunkInput[], opts?: { sourceId?: string } & BatchOpts): Promise<void> {
     return this.batchRetry(opts?.auditSite ?? 'upsertChunks', opts?.signal, () => this._upsertChunksOnce(slug, chunks, opts), chunks.length);
   }
 
-  private async _upsertChunksOnce(slug: string, chunks: ChunkInput[], opts?: { sourceId?: string; embeddingColumn?: ResolvedColumn }): Promise<void> {
+  private async _upsertChunksOnce(slug: string, chunks: ChunkInput[], opts?: { sourceId?: string }): Promise<void> {
     const sourceId = opts?.sourceId ?? 'default';
-    // #1262: caller-resolved write target for TEXT embeddings. Descriptor
-    // names are identifier-validated + quoted by buildVectorCastFragment;
-    // omitted => legacy `embedding vector`. Mirrors postgres-engine.ts.
-    const targetFragment = opts?.embeddingColumn
-      ? buildVectorCastFragment(opts.embeddingColumn)
-      : undefined;
-    const targetCol = targetFragment?.col ?? 'embedding';
-    const embeddingCast = targetFragment?.castSql.replace('$1::', '') ?? 'vector';
 
     // Source-scope the page-id lookup so duplicate slugs in different sources
     // do not return multiple rows or target the wrong page.
@@ -2279,7 +2270,7 @@ export class PGLiteEngine implements BrainEngine {
     // list. Image chunks pass embedding=null + embedding_image=Float32Array
     // (1024-dim Voyage). Text/code chunks pass embedding=Float32Array +
     // embedding_image=null. Default modality='text' when omitted.
-    const cols = `(page_id, chunk_index, chunk_text, chunk_source, ${targetCol}, model, token_count, embedded_at, language, symbol_name, symbol_type, start_line, end_line, parent_symbol_path, doc_comment, symbol_name_qualified, modality, embedding_image)`;
+    const cols = '(page_id, chunk_index, chunk_text, chunk_source, embedding, model, token_count, embedded_at, language, symbol_name, symbol_type, start_line, end_line, parent_symbol_path, doc_comment, symbol_name_qualified, modality, embedding_image)';
     const rowParts: string[] = [];
     const params: unknown[] = [];
     let paramIdx = 1;
@@ -2297,7 +2288,7 @@ export class PGLiteEngine implements BrainEngine {
       const modality = chunk.modality ?? 'text';
 
       // Inline ::vector NULL literals to avoid a per-branch placeholder.
-      const embeddingPh = embeddingStr ? `$${paramIdx++}::${embeddingCast}` : 'NULL';
+      const embeddingPh = embeddingStr ? `$${paramIdx++}::vector` : 'NULL';
       const embeddedAtPh = embeddingStr ? 'now()' : 'NULL';
       const embeddingImagePh = embeddingImageStr ? `$${paramIdx++}::vector` : 'NULL';
 
@@ -2336,19 +2327,19 @@ export class PGLiteEngine implements BrainEngine {
        ON CONFLICT (page_id, chunk_index) DO UPDATE SET
          chunk_text = EXCLUDED.chunk_text,
          chunk_source = EXCLUDED.chunk_source,
-         ${targetCol} = CASE
-           WHEN EXCLUDED.chunk_text != content_chunks.chunk_text THEN EXCLUDED.${targetCol}
-           WHEN content_chunks.${targetCol} IS NULL THEN EXCLUDED.${targetCol}
+         embedding = CASE
+           WHEN EXCLUDED.chunk_text != content_chunks.chunk_text THEN EXCLUDED.embedding
+           WHEN content_chunks.embedding IS NULL THEN EXCLUDED.embedding
            WHEN EXCLUDED.embedded_at IS NOT NULL
                 AND (content_chunks.embedded_at IS NULL OR EXCLUDED.embedded_at > content_chunks.embedded_at)
-                THEN EXCLUDED.${targetCol}
-           ELSE content_chunks.${targetCol}
+                THEN EXCLUDED.embedding
+           ELSE content_chunks.embedding
          END,
          model = COALESCE(EXCLUDED.model, content_chunks.model),
          token_count = EXCLUDED.token_count,
          embedded_at = CASE
-           WHEN EXCLUDED.chunk_text != content_chunks.chunk_text AND EXCLUDED.${targetCol} IS NULL THEN NULL
-           WHEN content_chunks.${targetCol} IS NULL AND EXCLUDED.${targetCol} IS NOT NULL THEN EXCLUDED.embedded_at
+           WHEN EXCLUDED.chunk_text != content_chunks.chunk_text AND EXCLUDED.embedding IS NULL THEN NULL
+           WHEN content_chunks.embedding IS NULL AND EXCLUDED.embedding IS NOT NULL THEN EXCLUDED.embedded_at
            WHEN EXCLUDED.embedded_at IS NOT NULL
                 AND (content_chunks.embedded_at IS NULL OR EXCLUDED.embedded_at > content_chunks.embedded_at)
                 THEN EXCLUDED.embedded_at
@@ -2386,19 +2377,14 @@ export class PGLiteEngine implements BrainEngine {
    * drift (NULL grandfathered → never stale). Shared by countStaleChunks +
    * sumStaleChunkChars so they can't drift.
    */
-  private buildStaleChunkWhere(opts?: { sourceId?: string; signature?: string; embeddingColumn?: ResolvedColumn }): { where: string; params: unknown[] } {
-    // #1262: staleness targets the caller-resolved write column when set
-    // (identifier-validated + quoted); legacy `embedding` otherwise.
-    const staleCol = opts?.embeddingColumn
-      ? buildVectorCastFragment(opts.embeddingColumn).col
-      : 'embedding';
+  private buildStaleChunkWhere(opts?: { sourceId?: string; signature?: string }): { where: string; params: unknown[] } {
     const params: unknown[] = [];
     const conds: string[] = [];
     if (opts?.signature !== undefined) {
       params.push(opts.signature);
-      conds.push(`(cc.${staleCol} IS NULL OR (p.embedding_signature IS NOT NULL AND p.embedding_signature <> $${params.length}))`);
+      conds.push(`(cc.embedding IS NULL OR (p.embedding_signature IS NOT NULL AND p.embedding_signature <> $${params.length}))`);
     } else {
-      conds.push(`cc.${staleCol} IS NULL`);
+      conds.push(`cc.embedding IS NULL`);
     }
     conds.push(`NOT (COALESCE(p.frontmatter, '{}'::jsonb) ? 'embed_skip')`);
     if (opts?.sourceId !== undefined) {
@@ -2408,7 +2394,7 @@ export class PGLiteEngine implements BrainEngine {
     return { where: conds.join(' AND '), params };
   }
 
-  async countStaleChunks(opts?: { sourceId?: string; signature?: string; embeddingColumn?: ResolvedColumn }): Promise<number> {
+  async countStaleChunks(opts?: { sourceId?: string; signature?: string }): Promise<number> {
     // D7: source-scoped count for `gbrain embed --stale --source X`. Always
     // JOIN pages so embed-skip + signature predicates apply. PGLite is
     // PostgreSQL 17.5 in WASM and supports the full JSONB operator set.
@@ -2424,7 +2410,7 @@ export class PGLiteEngine implements BrainEngine {
     return Number(count);
   }
 
-  async sumStaleChunkChars(opts?: { sourceId?: string; signature?: string; embeddingColumn?: ResolvedColumn }): Promise<number> {
+  async sumStaleChunkChars(opts?: { sourceId?: string; signature?: string }): Promise<number> {
     // Sibling of countStaleChunks: same stale predicate, summing chunk_text
     // length for the sync cost preview. ::bigint guards int4 overflow.
     const { where, params } = this.buildStaleChunkWhere(opts);
@@ -2477,17 +2463,11 @@ export class PGLiteEngine implements BrainEngine {
     sourceId?: string;
     orderBy?: 'page_id' | 'updated_desc';
     afterUpdatedAt?: string | null;
-    embeddingColumn?: ResolvedColumn;
   }): Promise<StaleChunkRow[]> {
     const limit = opts?.batchSize ?? 2000;
     const afterPid = opts?.afterPageId ?? 0;
     const afterIdx = opts?.afterChunkIndex ?? -1;
     const orderBy = opts?.orderBy ?? 'page_id';
-    // #1262: staleness follows the caller-resolved write column (validated +
-    // quoted identifier); legacy `embedding` otherwise.
-    const staleCol = opts?.embeddingColumn
-      ? buildVectorCastFragment(opts.embeddingColumn).col
-      : 'embedding';
 
     // v0.41.18.0 (A13, codex #9): --priority recent path. See postgres-engine
     // sibling for full rationale. Same composite cursor + ORDER BY.
@@ -2501,7 +2481,7 @@ export class PGLiteEngine implements BrainEngine {
                   p.updated_at
              FROM content_chunks cc
              JOIN pages p ON p.id = cc.page_id
-            WHERE cc.${staleCol} IS NULL
+            WHERE cc.embedding IS NULL
               AND NOT (COALESCE(p.frontmatter, '{}'::jsonb) ? 'embed_skip')
             ORDER BY p.updated_at DESC NULLS LAST, p.id ASC, cc.chunk_index ASC
             LIMIT $1`,
@@ -2512,7 +2492,7 @@ export class PGLiteEngine implements BrainEngine {
                   p.updated_at
              FROM content_chunks cc
              JOIN pages p ON p.id = cc.page_id
-            WHERE cc.${staleCol} IS NULL
+            WHERE cc.embedding IS NULL
               AND NOT (COALESCE(p.frontmatter, '{}'::jsonb) ? 'embed_skip')
               AND (
                 p.updated_at < $1::timestamptz
@@ -2531,7 +2511,7 @@ export class PGLiteEngine implements BrainEngine {
                 p.updated_at
            FROM content_chunks cc
            JOIN pages p ON p.id = cc.page_id
-          WHERE cc.${staleCol} IS NULL
+          WHERE cc.embedding IS NULL
             AND p.source_id = $1
             AND NOT (COALESCE(p.frontmatter, '{}'::jsonb) ? 'embed_skip')
           ORDER BY p.updated_at DESC NULLS LAST, p.id ASC, cc.chunk_index ASC
@@ -2543,7 +2523,7 @@ export class PGLiteEngine implements BrainEngine {
                 p.updated_at
            FROM content_chunks cc
            JOIN pages p ON p.id = cc.page_id
-          WHERE cc.${staleCol} IS NULL
+          WHERE cc.embedding IS NULL
             AND p.source_id = $1
             AND NOT (COALESCE(p.frontmatter, '{}'::jsonb) ? 'embed_skip')
             AND (
@@ -2568,7 +2548,7 @@ export class PGLiteEngine implements BrainEngine {
                 cc.model, cc.token_count, p.source_id, cc.page_id
            FROM content_chunks cc
            JOIN pages p ON p.id = cc.page_id
-          WHERE cc.${staleCol} IS NULL
+          WHERE cc.embedding IS NULL
             AND NOT (COALESCE(p.frontmatter, '{}'::jsonb) ? 'embed_skip')
             AND (cc.page_id, cc.chunk_index) > ($1, $2)
           ORDER BY cc.page_id, cc.chunk_index
@@ -2582,7 +2562,7 @@ export class PGLiteEngine implements BrainEngine {
               cc.model, cc.token_count, p.source_id, cc.page_id
          FROM content_chunks cc
          JOIN pages p ON p.id = cc.page_id
-        WHERE cc.${staleCol} IS NULL
+        WHERE cc.embedding IS NULL
           AND p.source_id = $1
           AND NOT (COALESCE(p.frontmatter, '{}'::jsonb) ? 'embed_skip')
           AND (cc.page_id, cc.chunk_index) > ($2, $3)

src/core/postgres-engine.ts

@@ -50,7 +50,6 @@ import type {
   BrainStats, BrainHealth,
   IngestLogEntry, IngestLogInput,
   EngineConfig,
-  ResolvedColumn,
   EvalCandidate, EvalCandidateInput,
   EvalCaptureFailure, EvalCaptureFailureReason,
   SalienceOpts, SalienceResult, AnomaliesOpts, AnomalyResult,
@@ -2381,21 +2380,13 @@ export class PostgresEngine implements BrainEngine {
   }
 
   // Chunks
-  async upsertChunks(slug: string, chunks: ChunkInput[], opts?: { sourceId?: string; embeddingColumn?: ResolvedColumn } & BatchOpts): Promise<void> {
+  async upsertChunks(slug: string, chunks: ChunkInput[], opts?: { sourceId?: string } & BatchOpts): Promise<void> {
     return this.batchRetry(opts?.auditSite ?? 'upsertChunks', opts?.signal, () => this._upsertChunksOnce(slug, chunks, opts), chunks.length);
   }
 
-  private async _upsertChunksOnce(slug: string, chunks: ChunkInput[], opts?: { sourceId?: string; embeddingColumn?: ResolvedColumn }): Promise<void> {
+  private async _upsertChunksOnce(slug: string, chunks: ChunkInput[], opts?: { sourceId?: string }): Promise<void> {
     const sql = this.sql;
     const sourceId = opts?.sourceId ?? 'default';
-    // #1262: caller-resolved write target for TEXT embeddings. Descriptor
-    // names are identifier-validated + quoted by buildVectorCastFragment;
-    // omitted => legacy `embedding vector`.
-    const targetFragment = opts?.embeddingColumn
-      ? buildVectorCastFragment(opts.embeddingColumn)
-      : undefined;
-    const targetCol = targetFragment?.col ?? 'embedding';
-    const embeddingCast = targetFragment?.castSql.replace('$1::', '') ?? 'vector';
 
     // Source-scope the page-id lookup. Without this filter, multi-source
     // brains where the slug exists in 2+ sources return >1 row and the
@@ -2422,7 +2413,7 @@ export class PostgresEngine implements BrainEngine {
     // scope metadata through upserts.
     // v0.27.1 (Phase 8): added `modality` + `embedding_image` to the column
     // list. Image chunks pass embedding=null + embedding_image=Float32Array.
-    const cols = `(page_id, chunk_index, chunk_text, chunk_source, ${targetCol}, model, token_count, embedded_at, language, symbol_name, symbol_type, start_line, end_line, parent_symbol_path, doc_comment, symbol_name_qualified, modality, embedding_image)`;
+    const cols = '(page_id, chunk_index, chunk_text, chunk_source, embedding, model, token_count, embedded_at, language, symbol_name, symbol_type, start_line, end_line, parent_symbol_path, doc_comment, symbol_name_qualified, modality, embedding_image)';
     const rows: string[] = [];
     const params: unknown[] = [];
     let paramIdx = 1;
@@ -2439,7 +2430,7 @@ export class PostgresEngine implements BrainEngine {
         : null;
       const modality = chunk.modality ?? 'text';
 
-      const embeddingPh = embeddingStr ? `$${paramIdx++}::${embeddingCast}` : 'NULL';
+      const embeddingPh = embeddingStr ? `$${paramIdx++}::vector` : 'NULL';
       const embeddedAtPh = embeddingStr ? 'now()' : 'NULL';
       const embeddingImagePh = embeddingImageStr ? `$${paramIdx++}::vector` : 'NULL';
 
@@ -2487,19 +2478,19 @@ export class PostgresEngine implements BrainEngine {
        ON CONFLICT (page_id, chunk_index) DO UPDATE SET
          chunk_text = EXCLUDED.chunk_text,
          chunk_source = EXCLUDED.chunk_source,
-         ${targetCol} = CASE
-           WHEN EXCLUDED.chunk_text != content_chunks.chunk_text THEN EXCLUDED.${targetCol}
-           WHEN content_chunks.${targetCol} IS NULL THEN EXCLUDED.${targetCol}
+         embedding = CASE
+           WHEN EXCLUDED.chunk_text != content_chunks.chunk_text THEN EXCLUDED.embedding
+           WHEN content_chunks.embedding IS NULL THEN EXCLUDED.embedding
            WHEN EXCLUDED.embedded_at IS NOT NULL
                 AND (content_chunks.embedded_at IS NULL OR EXCLUDED.embedded_at > content_chunks.embedded_at)
-                THEN EXCLUDED.${targetCol}
-           ELSE content_chunks.${targetCol}
+                THEN EXCLUDED.embedding
+           ELSE content_chunks.embedding
          END,
          model = COALESCE(EXCLUDED.model, content_chunks.model),
          token_count = EXCLUDED.token_count,
          embedded_at = CASE
-           WHEN EXCLUDED.chunk_text != content_chunks.chunk_text AND EXCLUDED.${targetCol} IS NULL THEN NULL
-           WHEN content_chunks.${targetCol} IS NULL AND EXCLUDED.${targetCol} IS NOT NULL THEN EXCLUDED.embedded_at
+           WHEN EXCLUDED.chunk_text != content_chunks.chunk_text AND EXCLUDED.embedding IS NULL THEN NULL
+           WHEN content_chunks.embedding IS NULL AND EXCLUDED.embedding IS NOT NULL THEN EXCLUDED.embedded_at
            WHEN EXCLUDED.embedded_at IS NOT NULL
                 AND (content_chunks.embedded_at IS NULL OR EXCLUDED.embedded_at > content_chunks.embedded_at)
                 THEN EXCLUDED.embedded_at
@@ -2539,19 +2530,14 @@ export class PostgresEngine implements BrainEngine {
    * embedding_signature drift (NULL grandfathered). Shared by
    * countStaleChunks + sumStaleChunkChars (parity with the PGLite sibling).
    */
-  private buildStaleChunkWhere(opts?: { sourceId?: string; signature?: string; embeddingColumn?: ResolvedColumn }): { where: string; params: unknown[] } {
-    // #1262: staleness targets the caller-resolved write column when set
-    // (identifier-validated + quoted); legacy `embedding` otherwise.
-    const staleCol = opts?.embeddingColumn
-      ? buildVectorCastFragment(opts.embeddingColumn).col
-      : 'embedding';
+  private buildStaleChunkWhere(opts?: { sourceId?: string; signature?: string }): { where: string; params: unknown[] } {
     const params: unknown[] = [];
     const conds: string[] = [];
     if (opts?.signature !== undefined) {
       params.push(opts.signature);
-      conds.push(`(cc.${staleCol} IS NULL OR (p.embedding_signature IS NOT NULL AND p.embedding_signature <> $${params.length}))`);
+      conds.push(`(cc.embedding IS NULL OR (p.embedding_signature IS NOT NULL AND p.embedding_signature <> $${params.length}))`);
     } else {
-      conds.push(`cc.${staleCol} IS NULL`);
+      conds.push(`cc.embedding IS NULL`);
     }
     conds.push(`NOT (COALESCE(p.frontmatter, '{}'::jsonb) ? 'embed_skip')`);
     if (opts?.sourceId !== undefined) {
@@ -2561,7 +2547,7 @@ export class PostgresEngine implements BrainEngine {
     return { where: conds.join(' AND '), params };
   }
 
-  async countStaleChunks(opts?: { sourceId?: string; signature?: string; embeddingColumn?: ResolvedColumn }): Promise<number> {
+  async countStaleChunks(opts?: { sourceId?: string; signature?: string }): Promise<number> {
     // Always JOIN pages so the embed_skip + signature predicates apply.
     // D7: source_id scoping. v0.41.31: optional signature widens staleness
     // to embedding_signature drift (NULL grandfathered).
@@ -2579,7 +2565,7 @@ export class PostgresEngine implements BrainEngine {
     });
   }
 
-  async sumStaleChunkChars(opts?: { sourceId?: string; signature?: string; embeddingColumn?: ResolvedColumn }): Promise<number> {
+  async sumStaleChunkChars(opts?: { sourceId?: string; signature?: string }): Promise<number> {
     // Sibling of countStaleChunks: same stale predicate, summing chunk_text
     // length for the sync cost preview. ::bigint guards int4 overflow.
     const { where, params } = this.buildStaleChunkWhere(opts);
@@ -2632,18 +2618,11 @@ export class PostgresEngine implements BrainEngine {
     sourceId?: string;
     orderBy?: 'page_id' | 'updated_desc';
     afterUpdatedAt?: string | null;
-    embeddingColumn?: ResolvedColumn;
   }): Promise<StaleChunkRow[]> {
     const limit = opts?.batchSize ?? 2000;
     const afterPid = opts?.afterPageId ?? 0;
     const afterIdx = opts?.afterChunkIndex ?? -1;
     const orderBy = opts?.orderBy ?? 'page_id';
-    // #1262: staleness follows the caller-resolved write column (validated +
-    // quoted identifier); legacy `embedding` otherwise. Interpolated below as
-    // an unsafe FRAGMENT (identifiers can't be bound parameters).
-    const staleCol = opts?.embeddingColumn
-      ? buildVectorCastFragment(opts.embeddingColumn).col
-      : 'embedding';
 
     // RLS scope binding (opt-in via GBRAIN_RLS_SCOPE_BINDING).
     return await this.withScopedReadTransaction(undefined, opts?.sourceId, async (tx) => {
@@ -2660,7 +2639,7 @@ export class PostgresEngine implements BrainEngine {
                    p.updated_at
             FROM content_chunks cc
             JOIN pages p ON p.id = cc.page_id
-            WHERE ${tx.unsafe(`cc.${staleCol} IS NULL`)}
+            WHERE cc.embedding IS NULL
               AND NOT (COALESCE(p.frontmatter, '{}'::jsonb) ? 'embed_skip')
             ORDER BY p.updated_at DESC NULLS LAST, p.id ASC, cc.chunk_index ASC
             LIMIT ${limit}
@@ -2670,7 +2649,7 @@ export class PostgresEngine implements BrainEngine {
                    p.updated_at
             FROM content_chunks cc
             JOIN pages p ON p.id = cc.page_id
-            WHERE ${tx.unsafe(`cc.${staleCol} IS NULL`)}
+            WHERE cc.embedding IS NULL
               AND NOT (COALESCE(p.frontmatter, '{}'::jsonb) ? 'embed_skip')
               AND (
                 p.updated_at < ${afterUpdated}::timestamptz
@@ -2688,7 +2667,7 @@ export class PostgresEngine implements BrainEngine {
                  p.updated_at
           FROM content_chunks cc
           JOIN pages p ON p.id = cc.page_id
-          WHERE ${tx.unsafe(`cc.${staleCol} IS NULL`)}
+          WHERE cc.embedding IS NULL
             AND p.source_id = ${opts.sourceId}
             AND NOT (COALESCE(p.frontmatter, '{}'::jsonb) ? 'embed_skip')
           ORDER BY p.updated_at DESC NULLS LAST, p.id ASC, cc.chunk_index ASC
@@ -2699,7 +2678,7 @@ export class PostgresEngine implements BrainEngine {
                  p.updated_at
           FROM content_chunks cc
           JOIN pages p ON p.id = cc.page_id
-          WHERE ${tx.unsafe(`cc.${staleCol} IS NULL`)}
+          WHERE cc.embedding IS NULL
             AND p.source_id = ${opts.sourceId}
             AND NOT (COALESCE(p.frontmatter, '{}'::jsonb) ? 'embed_skip')
             AND (
@@ -2719,7 +2698,7 @@ export class PostgresEngine implements BrainEngine {
                  cc.model, cc.token_count, p.source_id, cc.page_id
           FROM content_chunks cc
           JOIN pages p ON p.id = cc.page_id
-          WHERE ${tx.unsafe(`cc.${staleCol} IS NULL`)}
+          WHERE cc.embedding IS NULL
             AND NOT (COALESCE(p.frontmatter, '{}'::jsonb) ? 'embed_skip')
             AND (cc.page_id, cc.chunk_index) > (${afterPid}, ${afterIdx})
           ORDER BY cc.page_id, cc.chunk_index
@@ -2732,7 +2711,7 @@ export class PostgresEngine implements BrainEngine {
                cc.model, cc.token_count, p.source_id, cc.page_id
         FROM content_chunks cc
         JOIN pages p ON p.id = cc.page_id
-        WHERE ${tx.unsafe(`cc.${staleCol} IS NULL`)}
+        WHERE cc.embedding IS NULL
           AND p.source_id = ${opts.sourceId}
           AND NOT (COALESCE(p.frontmatter, '{}'::jsonb) ? 'embed_skip')
           AND (cc.page_id, cc.chunk_index) > (${afterPid}, ${afterIdx})

src/core/search/embedding-column.ts

@@ -443,80 +443,6 @@ export function resolveEmbeddingColumn(
   };
 }
 
-/**
- * Resolves the WRITE-side embedding column for the currently configured
- * embedding model (#1262). The read-side resolver above answers "which
- * column does this query search?"; this one answers "which column should
- * newly produced text embeddings land in?".
- *
- * Unlike read-side search, writes take no per-call column override. The
- * import/embed boundary resolves once from merged config + gateway state
- * and passes the descriptor into `engine.upsertChunks`; engines stay
- * config-free (same contract as the read-side descriptor).
- *
- * Behavior:
- *   - no user-declared `embedding_columns` => undefined (legacy brain,
- *     writes keep targeting the default `embedding` column)
- *   - a user-declared entry whose `provider` matches the current
- *     embedding model => that entry's descriptor
- *   - no provider match => undefined (fall back to legacy `embedding`)
- *
- * Only USER-declared entries are consulted — never the cfg-derived
- * builtins. The `embedding_image` builtin's provider is the multimodal
- * model; matching it here would misroute text embeddings into the image
- * column. The no-match fallback is intentional: switching models before
- * registering a matching column must not silently write vectors into an
- * arbitrary column.
- */
-export function resolveWriteColumn(cfg: GBrainConfig): ResolvedColumn | undefined {
-  const userColumns = cfg.embedding_columns;
-  if (
-    !userColumns ||
-    typeof userColumns !== 'object' ||
-    Array.isArray(userColumns) ||
-    Object.keys(userColumns).length === 0
-  ) {
-    return undefined;
-  }
-
-  // Same model-resolution chain as the registry builtin: cfg > gateway > default.
-  let gwModel: string | undefined;
-  try {
-    const gw = require('../ai/gateway.ts') as typeof import('../ai/gateway.ts');
-    gwModel = gw.getEmbeddingModel();
-  } catch {
-    // Gateway unconfigured — fall through to the canonical default.
-  }
-  const currentModel = cfg.embedding_model ?? gwModel ?? DEFAULT_EMBEDDING_MODEL;
-
-  for (const [name, entry] of Object.entries(userColumns)) {
-    if (!entry) continue;
-    validateColumnKey(name);
-    validateColumnConfig(name, entry);
-    if (entry.provider !== currentModel) continue;
-    return {
-      name,
-      type: entry.type,
-      dimensions: entry.dimensions,
-      embeddingModel: entry.provider,
-    };
-  }
-  return undefined;
-}
-
-/**
- * Engine-boundary convenience: merged config (file/env + DB plane) →
- * resolveWriteColumn. Dynamic import keeps config.ts out of this module's
- * static graph (mirrors the gateway require above).
- */
-export async function resolveWriteColumnForEngine(
-  engine: { getConfig(key: string): Promise<string | null | undefined> },
-): Promise<ResolvedColumn | undefined> {
-  const { loadConfigWithEngine } = await import('../config.ts');
-  const cfg = await loadConfigWithEngine(engine);
-  return cfg ? resolveWriteColumn(cfg) : undefined;
-}
-
 /**
  * True when the resolved column is the default `embedding` name.
  * Name-based check; does not compare embedding space.

src/core/skillopt/orchestrator.ts

@@ -93,7 +93,13 @@ import { resolveLrSchedule } from './lr-schedule.ts';
 import { preflight, formatPreflightReport } from './preflight.ts';
 import { isRejected, loadRejectedBuffer, makeRejectedEntry, saveRejectedBuffer } from './rejected-buffer.ts';
 import { runReflect, runOneShotRewrite, describeJudges } from './reflect.ts';
-import { acceptCandidate, bestPath, revertAllPending, skillPath, writeProposed } from './version-store.ts';
+import {
+  acceptCandidate,
+  proposedPath as proposedFilePath,
+  revertAllPending,
+  skillPath,
+  writeProposed,
+} from './version-store.ts';
 import { runValidationGate, scoreSkillOnTasks } from './validate-gate.ts';
 import { ROLLOUT_SUCCESS_THRESHOLD } from './types.ts';
 import type { SkillOptOpts, EditOp, RunReceipt, BenchmarkTask } from './types.ts';
@@ -702,9 +708,9 @@ async function runOptimizationLoop(
   // to the catch's assignment values only (it can't prove the async callback ran).
   const finalOutcome = outcome as 'accepted' | 'no_improvement' | 'aborted' | 'errored';
   if (!mutateDecision.mutate && finalOutcome === 'accepted') {
-    // best.md was written by writeProposed() in the accept branch (no-mutate
-    // path); it doubles as proposed.md for human review. SKILL.md untouched.
-    proposedPath = bestPath(skillsDir, skillName);
+    // writeProposed() emitted both the best pointer and the stable review
+    // artifact in the accept branch. SKILL.md remains untouched.
+    proposedPath = proposedFilePath(skillsDir, skillName);
   } else if (mutateDecision.mutate) {
     mutatedSkillFile = finalOutcome === 'accepted';
   }

src/core/skillopt/version-store.ts

@@ -23,6 +23,7 @@
  *
  *   history.json
  *   best.md
+ *   proposed.md
  *   versions/
  *     v0001_e1_s1.md
  *     v0002_e1_s2.md
@@ -52,6 +53,10 @@ export function bestPath(skillsDir: string, skillName: string): string {
   return path.join(skilloptDir(skillsDir, skillName), 'best.md');
 }
 
+export function proposedPath(skillsDir: string, skillName: string): string {
+  return path.join(skilloptDir(skillsDir, skillName), 'proposed.md');
+}
+
 export function skillPath(skillsDir: string, skillName: string): string {
   return path.join(skillsDir, skillName, 'SKILL.md');
 }
@@ -171,17 +176,18 @@ export function acceptCandidate(input: AcceptInput): AcceptResult {
 }
 
 /**
- * Write the candidate to `best.md` (which doubles as `proposed.md`) WITHOUT
- * touching SKILL.md or the history ledger. Used by the `--no-mutate` /
- * bundled-without-allow paths: the optimizer found a better candidate but the
- * caller opted out of in-place mutation, so we surface it for human review.
- * Returns the path written. Atomic (.tmp + rename).
+ * Write the candidate to both `best.md` and `proposed.md` WITHOUT touching
+ * SKILL.md or the history ledger. `best.md` remains the optimizer's current
+ * best pointer; `proposed.md` is the stable human-review artifact promised by
+ * `--no-mutate`. Returns the proposal path. Each write is atomic (.tmp + rename).
  */
 export function writeProposed(skillsDir: string, skillName: string, candidateText: string): string {
-  const p = bestPath(skillsDir, skillName);
-  fs.mkdirSync(path.dirname(p), { recursive: true });
-  atomicWrite(p, candidateText);
-  return p;
+  const best = bestPath(skillsDir, skillName);
+  const proposed = proposedPath(skillsDir, skillName);
+  fs.mkdirSync(path.dirname(best), { recursive: true });
+  atomicWrite(best, candidateText);
+  atomicWrite(proposed, candidateText);
+  return proposed;
 }
 
 /**

test/e2e/embedding-column-pglite.test.ts

@@ -241,136 +241,3 @@ describe('buildVectorCastFragment — engine SQL composer (D3)', () => {
     expect(castSql).toBe('$1::halfvec(2560)');
   });
 });
-
-describe('PGLite engine: upsertChunks write-side ResolvedColumn descriptor (#1262)', () => {
-  test('halfvec descriptor writes the text embedding to the alternate column, not legacy embedding', async () => {
-    await engine.putPage('docs/write-alt-pglite', {
-      type: 'concept',
-      title: 'Write alt column PGLite',
-      compiled_truth: 'PGLite write-side alternate embedding column test.',
-    });
-
-    const descriptor: ResolvedColumn = {
-      name: 'embedding_ze',
-      type: 'halfvec',
-      dimensions: 2560,
-      embeddingModel: 'zeroentropyai:zembed-1',
-    };
-    await engine.upsertChunks('docs/write-alt-pglite', [
-      {
-        chunk_index: 0,
-        chunk_text: 'PGLite write-side alternate embedding column test.',
-        chunk_source: 'compiled_truth',
-        embedding: new Float32Array(2560).fill(0.25),
-      },
-    ], { embeddingColumn: descriptor });
-
-    const rows = await engine.executeRaw<{
-      has_default: boolean;
-      has_ze: boolean;
-      has_embedded_at: boolean;
-    }>(
-      `SELECT embedding IS NOT NULL AS has_default,
-              embedding_ze IS NOT NULL AS has_ze,
-              embedded_at IS NOT NULL AS has_embedded_at
-         FROM content_chunks cc
-         JOIN pages p ON p.id = cc.page_id
-        WHERE p.slug = 'docs/write-alt-pglite'`,
-    );
-    expect(rows.length).toBe(1);
-    expect(rows[0].has_default).toBe(false);
-    expect(rows[0].has_ze).toBe(true);
-    expect(rows[0].has_embedded_at).toBe(true);
-  });
-
-  test('text-unchanged re-upsert without a vector preserves the alternate-column embedding', async () => {
-    const descriptor: ResolvedColumn = {
-      name: 'embedding_ze',
-      type: 'halfvec',
-      dimensions: 2560,
-      embeddingModel: 'zeroentropyai:zembed-1',
-    };
-    // Same chunk_text, no embedding: the ON CONFLICT CASE must keep the
-    // existing alternate-column vector (D24 semantics follow the column).
-    await engine.upsertChunks('docs/write-alt-pglite', [
-      {
-        chunk_index: 0,
-        chunk_text: 'PGLite write-side alternate embedding column test.',
-        chunk_source: 'compiled_truth',
-      },
-    ], { embeddingColumn: descriptor });
-    const rows = await engine.executeRaw<{ has_ze: boolean }>(
-      `SELECT embedding_ze IS NOT NULL AS has_ze
-         FROM content_chunks cc
-         JOIN pages p ON p.id = cc.page_id
-        WHERE p.slug = 'docs/write-alt-pglite'`,
-    );
-    expect(rows).toEqual([{ has_ze: true }]);
-  });
-});
-
-describe('PGLite: embed --stale converges on an alt-column brain (#1262)', () => {
-  test('boundary resolves the write column; stale scan does not re-select embedded rows', async () => {
-    const { runEmbedCore } = await import('../../src/commands/embed.ts');
-    const local = new PGLiteEngine();
-    const previousHome = process.env.GBRAIN_HOME;
-    process.env.GBRAIN_HOME = `/tmp/gbrain-write-col-stale-${Date.now()}`;
-    try {
-      await local.connect({});
-      await local.initSchema();
-      await (local as any).db.exec(
-        `ALTER TABLE content_chunks ADD COLUMN IF NOT EXISTS embedding_ze halfvec(2560)`,
-      );
-
-      const descriptor: ResolvedColumn = {
-        name: 'embedding_ze',
-        type: 'halfvec',
-        dimensions: 2560,
-        embeddingModel: 'zeroentropyai:zembed-1',
-      };
-      await local.setConfig('embedding_columns', JSON.stringify({
-        embedding_ze: { provider: 'zeroentropyai:zembed-1', dimensions: 2560, type: 'halfvec' },
-      }));
-      configureGateway({
-        embedding_model: 'zeroentropyai:zembed-1',
-        embedding_dimensions: 2560,
-        env: {},
-      });
-
-      await local.putPage('docs/stale-alt-pglite', {
-        type: 'concept',
-        title: 'Dynamic stale column',
-        compiled_truth: 'A chunk that is embedded only in the dynamic column.',
-      });
-      await local.upsertChunks('docs/stale-alt-pglite', [
-        {
-          chunk_index: 0,
-          chunk_text: 'A chunk that is embedded only in the dynamic column.',
-          chunk_source: 'compiled_truth',
-          embedding: new Float32Array(2560).fill(0.25),
-        },
-      ], { embeddingColumn: descriptor });
-
-      // Engine-level contrast: legacy predicate still sees the row as stale;
-      // the alt-column predicate does not.
-      expect(await local.countStaleChunks()).toBe(1);
-      expect(await local.countStaleChunks({ embeddingColumn: descriptor })).toBe(0);
-      // sumStaleChunkChars feeds the sync cost gate — same predicate contract.
-      expect(await local.sumStaleChunkChars()).toBeGreaterThan(0);
-      expect(await local.sumStaleChunkChars({ embeddingColumn: descriptor })).toBe(0);
-      expect(await local.listStaleChunks({ embeddingColumn: descriptor, batchSize: 100 })).toHaveLength(0);
-      expect(await local.listStaleChunks({ batchSize: 100 })).toHaveLength(1);
-
-      // Boundary-level: `embed --stale --dry-run` resolves the write column
-      // from merged config + gateway and reports NOTHING to embed. Without
-      // the fix this reports 1 (perpetual re-embed loop).
-      const result = await runEmbedCore(local, { stale: true, dryRun: true });
-      expect(result.would_embed).toBe(0);
-    } finally {
-      await local.disconnect();
-      if (previousHome === undefined) delete process.env.GBRAIN_HOME;
-      else process.env.GBRAIN_HOME = previousHome;
-      resetGateway();
-    }
-  });
-});

test/e2e/embedding-column-postgres.test.ts

@@ -224,54 +224,4 @@ if (!dbUrl) {
       await engine.executeRaw(`UPDATE content_chunks SET embedding_voyage = '${v}'::vector WHERE id = ${dogId}`);
     });
   });
-
-  describe('Postgres: upsertChunks write-side ResolvedColumn descriptor (#1262)', () => {
-    const descriptor: ResolvedColumn = {
-      name: 'embedding_ze',
-      type: 'halfvec',
-      dimensions: 2560,
-      embeddingModel: 'zeroentropyai:zembed-1',
-    };
-
-    test('halfvec descriptor writes the text embedding to the alternate column, not legacy embedding', async () => {
-      await engine.putPage('docs/write-alt-postgres', {
-        type: 'concept',
-        title: 'Write alt column Postgres',
-        compiled_truth: 'Postgres write-side alternate embedding column test.',
-      });
-      await engine.upsertChunks('docs/write-alt-postgres', [
-        {
-          chunk_index: 0,
-          chunk_text: 'Postgres write-side alternate embedding column test.',
-          chunk_source: 'compiled_truth',
-          embedding: new Float32Array(2560).fill(0.25),
-        },
-      ], { embeddingColumn: descriptor });
-
-      const rows = await engine.executeRaw<{
-        has_default: boolean;
-        has_ze: boolean;
-      }>(
-        `SELECT embedding IS NOT NULL AS has_default,
-                embedding_ze IS NOT NULL AS has_ze
-           FROM content_chunks cc
-           JOIN pages p ON p.id = cc.page_id
-          WHERE p.slug = 'docs/write-alt-postgres'`,
-      );
-      expect(rows.length).toBe(1);
-      expect(rows[0].has_default).toBe(false);
-      expect(rows[0].has_ze).toBe(true);
-    }, 30_000);
-
-    test('stale scan follows the write-side column (count + list parity with the write target)', async () => {
-      // Legacy predicate: cat/dog/write-alt rows all have embedding NULL.
-      expect(await engine.countStaleChunks()).toBeGreaterThan(0);
-      // Alt-column predicate: every chunk has embedding_ze populated.
-      expect(await engine.countStaleChunks({ embeddingColumn: descriptor })).toBe(0);
-      expect(await engine.listStaleChunks({ embeddingColumn: descriptor, batchSize: 100 })).toHaveLength(0);
-      expect((await engine.listStaleChunks({ batchSize: 100 })).length).toBeGreaterThan(0);
-      // updated_desc arm uses the same predicate.
-      expect(await engine.listStaleChunks({ embeddingColumn: descriptor, orderBy: 'updated_desc', batchSize: 100 })).toHaveLength(0);
-    }, 30_000);
-  });
 }

test/e2e/skillopt-loop.serial.test.ts

@@ -39,6 +39,7 @@ import { runSkillOpt } from '../../src/core/skillopt/orchestrator.ts';
 import {
   bestPath,
   loadHistory,
+  proposedPath,
   skillPath,
 } from '../../src/core/skillopt/version-store.ts';
 import { loadRejectedBuffer } from '../../src/core/skillopt/rejected-buffer.ts';
@@ -741,7 +742,7 @@ describe('skillopt T3 — F11 held-out gate, ablation opts, no-DB-pollution', ()
     } finally { fixture.cleanup(); }
   });
 
-  test('--no-mutate writes proposed.md (best.md), leaves SKILL.md untouched', async () => {
+  test('--no-mutate writes proposed.md and best.md, leaves SKILL.md untouched', async () => {
     const fixture = setupFixture(SKILL_PEOPLE_ONLY, CITATIONS_BENCHMARK);
     try {
       installStub({
@@ -753,10 +754,9 @@ describe('skillopt T3 — F11 held-out gate, ablation opts, no-DB-pollution', ()
           const result = await runOnce(fixture, { noMutate: true });
           expect(result.outcome).toBe('accepted');
           expect(result.mutatedSkillFile).toBe(false);
-          expect(result.proposedPath).toBeDefined();
-          // proposed.md (best.md) exists and carries the improvement.
-          expect(fs.existsSync(result.proposedPath!)).toBe(true);
+          expect(result.proposedPath).toBe(proposedPath(fixture.skillsDir, SKILL));
           expect(fs.readFileSync(result.proposedPath!, 'utf8')).toContain('## Citations');
+          expect(fs.readFileSync(bestPath(fixture.skillsDir, SKILL), 'utf8')).toContain('## Citations');
           // SKILL.md on disk is UNCHANGED (still People-only).
           const skill = fs.readFileSync(skillPath(fixture.skillsDir, SKILL), 'utf8');
           expect(skill).not.toContain('## Citations');

test/search/embedding-column.serial.test.ts

@@ -13,10 +13,9 @@
  *     throw on unknown string.
  */
 
-import { describe, test, expect, afterAll, afterEach } from 'bun:test';
+import { describe, test, expect } from 'bun:test';
 import {
   resolveEmbeddingColumn,
-  resolveWriteColumn,
   getEmbeddingColumnRegistry,
   buildVectorCastFragment,
   quoteIdentifier,
@@ -35,28 +34,6 @@ import {
 } from '../../src/core/search/embedding-column.ts';
 import type { GBrainConfig } from '../../src/core/config.ts';
 import type { ResolvedColumn } from '../../src/core/types.ts';
-import { configureGateway, resetGateway } from '../../src/core/ai/gateway.ts';
-
-/**
- * Teardown: reset AND re-apply the legacy preload config
- * (test/helpers/legacy-embedding-preload.ts). A bare resetGateway() would
- * leave the slot empty for the NEXT file's beforeAll (the preload's
- * per-test beforeEach only fires before tests, not before beforeAll), which
- * would make sibling PGLite fixtures initSchema at the 1280 default instead
- * of the legacy 1536 their seed vectors assume.
- */
-function restorePreloadGateway() {
-  resetGateway();
-  configureGateway({
-    embedding_model: 'openai:text-embedding-3-large',
-    embedding_dimensions: 1536,
-    env: { ...process.env },
-  });
-}
-
-afterAll(() => {
-  restorePreloadGateway();
-});
 
 function cfg(overrides: Partial<GBrainConfig> = {}): GBrainConfig {
   return { engine: 'pglite', ...overrides };
@@ -545,89 +522,3 @@ describe('codex /ship #4 — isCacheSafe (embedding-space-based skip)', () => {
     expect(isCacheSafe(r, cfg())).toBe(true);
   });
 });
-
-describe('resolveWriteColumn — write-side boundary resolution (#1262)', () => {
-  afterEach(() => {
-    restorePreloadGateway();
-  });
-
-  test('no registry / empty registry returns undefined (legacy single-column brain)', () => {
-    expect(resolveWriteColumn(cfg())).toBeUndefined();
-    expect(resolveWriteColumn(cfg({ embedding_columns: {} }))).toBeUndefined();
-  });
-
-  test('provider match via cfg.embedding_model returns the descriptor', () => {
-    const r = resolveWriteColumn(cfg({
-      embedding_model: 'voyage:voyage-3-large',
-      embedding_dimensions: 1024,
-      embedding_columns: {
-        embedding_voyage: { provider: 'voyage:voyage-3-large', dimensions: 1024, type: 'vector' },
-      },
-    }));
-    expect(r).toEqual({
-      name: 'embedding_voyage',
-      type: 'vector',
-      dimensions: 1024,
-      embeddingModel: 'voyage:voyage-3-large',
-    });
-  });
-
-  test('provider match via gateway state (cfg.embedding_model unset) returns descriptor', () => {
-    configureGateway({
-      embedding_model: 'zeroentropyai:zembed-1',
-      embedding_dimensions: 2560,
-      env: {},
-    });
-    const r = resolveWriteColumn(cfg({
-      embedding_columns: {
-        embedding_ze: { provider: 'zeroentropyai:zembed-1', dimensions: 2560, type: 'halfvec' },
-      },
-    }));
-    expect(r).toEqual({
-      name: 'embedding_ze',
-      type: 'halfvec',
-      dimensions: 2560,
-      embeddingModel: 'zeroentropyai:zembed-1',
-    });
-  });
-
-  test('no provider match returns undefined instead of guessing a column', () => {
-    configureGateway({
-      embedding_model: 'zeroentropyai:zembed-1',
-      embedding_dimensions: 2560,
-      env: {},
-    });
-    const r = resolveWriteColumn(cfg({
-      embedding_columns: {
-        embedding_voyage: { provider: 'voyage:voyage-3-large', dimensions: 1024, type: 'vector' },
-      },
-    }));
-    expect(r).toBeUndefined();
-  });
-
-  test('only USER-declared columns are consulted — multimodal builtin never captures text writes', () => {
-    // Current model equals the embedding_image BUILTIN's provider; a registry
-    // walk that consulted builtins would misroute text writes into the image
-    // column. resolveWriteColumn must return undefined here.
-    configureGateway({
-      embedding_model: 'voyage:voyage-multimodal-3',
-      embedding_dimensions: 1024,
-      env: {},
-    });
-    const r = resolveWriteColumn(cfg({
-      embedding_columns: {
-        embedding_other: { provider: 'openai:text-embedding-3-large', dimensions: 1536, type: 'vector' },
-      },
-    }));
-    expect(r).toBeUndefined();
-  });
-
-  test('malformed registry entry throws loud (same validation as the read side)', () => {
-    expect(() => resolveWriteColumn(cfg({
-      embedding_model: 'voyage:voyage-3-large',
-      embedding_columns: {
-        'bad"col': { provider: 'voyage:voyage-3-large', dimensions: 1024, type: 'vector' },
-      } as never,
-    }))).toThrow(EmbeddingColumnConfigError);
-  });
-});

test/skillopt/version-store.test.ts

@@ -12,9 +12,11 @@ import {
   bestPath,
   historyPath,
   loadHistory,
+  proposedPath,
   revertAllPending,
   skillPath,
   versionsDir,
+  writeProposed,
 } from '../../src/core/skillopt/version-store.ts';
 
 let tmpDir: string;
@@ -79,6 +81,19 @@ describe('acceptCandidate (D8 two-phase commit)', () => {
   });
 });
 
+describe('writeProposed', () => {
+  test('writes distinct best and proposed artifacts without mutating SKILL.md (#2635)', () => {
+    const candidate = '---\nname: test\n---\nproposed body\n';
+
+    const written = writeProposed(tmpDir, SKILL, candidate);
+
+    expect(written).toBe(proposedPath(tmpDir, SKILL));
+    expect(fs.readFileSync(bestPath(tmpDir, SKILL), 'utf8')).toBe(candidate);
+    expect(fs.readFileSync(proposedPath(tmpDir, SKILL), 'utf8')).toBe(candidate);
+    expect(fs.readFileSync(skillPath(tmpDir, SKILL), 'utf8')).toContain('baseline body');
+  });
+});
+
 describe('revertAllPending (D8 crash recovery)', () => {
   test('no-op when no pending rows', () => {
     const reverted = revertAllPending(tmpDir, SKILL);