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/init.ts

@@ -161,7 +161,7 @@ interface ResolveAIOptionsArgs {
   nonInteractive: boolean;       // --non-interactive (forces D3 fail-loud, no picker)
 }
 
-export interface ResolvedAIOptions {
+interface ResolvedAIOptions {
   embedding_model?: string;
   embedding_dimensions?: number;
   expansion_model?: string;
@@ -170,41 +170,6 @@ export interface ResolvedAIOptions {
   noEmbedding?: boolean;
 }
 
-/**
- * Seed init's AI options from persisted config, falling back to the raw env
- * vars when loadConfig() returned null (#1058). On a cold install (no
- * config.json AND no DATABASE_URL) loadConfig short-circuits BEFORE its env
- * merge, so GBRAIN_EMBEDDING_MODEL / GBRAIN_EMBEDDING_DIMENSIONS /
- * GBRAIN_EXPANSION_MODEL / GBRAIN_CHAT_MODEL were silently ignored by init
- * and Tier-3 detection auto-picked by API key instead. Exported for unit
- * tests (env injectable).
- */
-export function seedAIOptionsFromConfig(
-  cfg: GBrainConfig | null,
-  env: NodeJS.ProcessEnv = process.env,
-): ResolvedAIOptions {
-  const envDims = env.GBRAIN_EMBEDDING_DIMENSIONS
-    ? parseInt(env.GBRAIN_EMBEDDING_DIMENSIONS, 10)
-    : NaN;
-  const seed = cfg ?? {
-    embedding_disabled: undefined,
-    embedding_model: env.GBRAIN_EMBEDDING_MODEL,
-    embedding_dimensions: Number.isFinite(envDims) ? envDims : undefined,
-    expansion_model: env.GBRAIN_EXPANSION_MODEL,
-    chat_model: env.GBRAIN_CHAT_MODEL,
-  };
-  const out: ResolvedAIOptions = {};
-  if (seed.embedding_disabled) {
-    out.noEmbedding = true;
-  } else if (seed.embedding_model) {
-    out.embedding_model = seed.embedding_model;
-    if (seed.embedding_dimensions) out.embedding_dimensions = seed.embedding_dimensions;
-  }
-  if (seed.expansion_model) out.expansion_model = seed.expansion_model;
-  if (seed.chat_model) out.chat_model = seed.chat_model;
-  return out;
-}
-
 /**
  * Resolve AI provider options for `gbrain init`.
  *
@@ -238,13 +203,18 @@ async function resolveAIOptions(opts: ResolveAIOptionsArgs): Promise<ResolvedAIO
   // user already opted into deferred mode.
   try {
     const { loadConfig } = await import('../core/config.ts');
-    // #1058: loadConfig() returns null on a cold install (no config.json AND
-    // no DATABASE_URL) — before it ever reaches its env merge. The seed helper
-    // falls back to the same GBRAIN_* env vars directly in that case.
-    Object.assign(out, seedAIOptionsFromConfig(loadConfig()));
+    const cfg = loadConfig();
+    if (cfg?.embedding_disabled) {
+      out.noEmbedding = true;
+    } else if (cfg?.embedding_model) {
+      out.embedding_model = cfg.embedding_model;
+      if (cfg.embedding_dimensions) out.embedding_dimensions = cfg.embedding_dimensions;
+    }
+    if (cfg?.expansion_model) out.expansion_model = cfg.expansion_model;
+    if (cfg?.chat_model) out.chat_model = cfg.chat_model;
   } catch {
-    // loadConfig threw — treat as first-time install, fall through to env
-    // detection.
+    // loadConfig throws when no brain configured — first-time install, fall
+    // through to env detection.
   }
 
   // --- Tier 1+2: explicit flags ---------------------------------------------

src/core/operations.ts

@@ -332,15 +332,6 @@ export interface OperationContext {
    * remote/untrusted (defense in depth in case the type is bypassed via cast).
    */
   remote: boolean;
-  /**
-   * Transport marker for auth-less remote surfaces (#1061). The stdio MCP
-   * dispatch sets 'stdio' — it is deliberately `remote: true` (agent-facing,
-   * untrusted) but has no per-token auth (local pipe), so identity ops like
-   * whoami need a way to distinguish "known auth-less transport" from "a
-   * transport bug forgot to thread ctx.auth". Trust decisions MUST NOT key
-   * off this field — only `ctx.remote === false` grants trust.
-   */
-  transport?: 'stdio';
   /**
    * Subagent runtime context (v0.16+). Set by the subagent tool dispatcher when
    * dispatching an op as a tool call from an LLM loop. Used to enforce per-op
@@ -3722,10 +3713,9 @@ const whoami: Operation = {
     'Introspect the calling identity. Returns one of three transport shapes: ' +
     '{transport: "oauth", client_id, client_name, scopes, expires_at}, ' +
     '{transport: "legacy", token_name, scopes, expires_at: null}, or ' +
-    '{transport: "local", scopes: []}, or {transport: "stdio", scopes: []} ' +
-    'for the auth-less stdio MCP pipe. Throws unknown_transport when the ' +
-    'context is ambiguous (remote=true without auth and no transport marker) ' +
-    '— fail-closed posture mirroring the v0.26.9 trust-boundary contract.',
+    '{transport: "local", scopes: []}. Throws unknown_transport when the ' +
+    'context is ambiguous (remote=true without auth) — fail-closed posture ' +
+    'mirroring the v0.26.9 trust-boundary contract.',
   params: {},
   scope: 'read',
   handler: async (ctx) => {
@@ -3737,12 +3727,6 @@ const whoami: Operation = {
     if (ctx.remote === false) {
       return { transport: 'local', scopes: [] };
     }
-    // #1061: stdio MCP is remote/untrusted by design but has no per-token
-    // auth (local pipe) — a known transport, not a bug. Report it instead of
-    // throwing. Empty scopes: nothing here may be used to gate anything.
-    if (!ctx.auth && ctx.transport === 'stdio') {
-      return { transport: 'stdio', scopes: [] };
-    }
     if (!ctx.auth) {
       throw new OperationError(
         'unknown_transport',

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;
 }
 
 /**

src/mcp/dispatch.ts

@@ -32,12 +32,6 @@ export interface DispatchOpts {
   remote?: boolean;
   /** Override the default stderr logger (e.g. CLI uses console.* directly). */
   logger?: OperationContext['logger'];
-  /**
-   * #1061: transport marker for auth-less remote surfaces. The stdio MCP
-   * server passes 'stdio' so identity ops (whoami) can report the transport
-   * instead of throwing unknown_transport. Never used for trust decisions.
-   */
-  transport?: OperationContext['transport'];
   /**
    * v0.28: per-token allow-list for the takes.holder field. Threaded by
    * the HTTP/stdio transport from `access_tokens.permissions.takes_holders`.
@@ -209,7 +203,6 @@ export function buildOperationContext(
     logger: opts.logger || stderrLogger,
     dryRun: !!params.dry_run,
     remote: opts.remote ?? true,
-    transport: opts.transport,
     takesHoldersAllowList: opts.takesHoldersAllowList,
     // v0.34 D4: sourceId is REQUIRED at the type level. Auto-fill 'default'
     // for single-source brains and any caller who didn't resolve a sourceId.

src/mcp/server.ts

@@ -42,10 +42,6 @@ export async function startMcpServer(engine: BrainEngine) {
     // `gbrain call <op>` (sets remote=false in src/cli.ts).
     return dispatchToolCall(engine, name, params, {
       remote: true,
-      // #1061: mark the transport so whoami can report {transport: 'stdio'}
-      // instead of throwing unknown_transport. Trust posture unchanged —
-      // stdio stays remote/untrusted.
-      transport: 'stdio',
       takesHoldersAllowList: ['world'],
       // v0.31: source defaults to 'default' for stdio (no per-token scope).
       // Operators who want a different source on stdio MCP should set

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/init-env-detection.test.ts

@@ -12,7 +12,7 @@
  */
 
 import { describe, test, expect } from 'bun:test';
-import { groupReadyByProvider, findEnvKeyTypos, seedAIOptionsFromConfig } from '../src/commands/init.ts';
+import { groupReadyByProvider, findEnvKeyTypos } from '../src/commands/init.ts';
 
 describe('groupReadyByProvider — embedding touchpoint', () => {
   test('OPENAI_API_KEY alone → openai is ready', async () => {
@@ -149,47 +149,3 @@ describe('findEnvKeyTypos', () => {
     expect(got.find(t => t.userSet === 'COMPLETELY_UNRELATED_KEY')).toBeUndefined();
   });
 });
-
-describe('seedAIOptionsFromConfig — #1058 cold-install env fallback', () => {
-  test('null config (no config.json, no DATABASE_URL) falls back to GBRAIN_* env vars', () => {
-    const got = seedAIOptionsFromConfig(null, {
-      GBRAIN_EMBEDDING_MODEL: 'voyage:voyage-3-large',
-      GBRAIN_EMBEDDING_DIMENSIONS: '1024',
-      GBRAIN_EXPANSION_MODEL: 'openai:gpt-5-mini',
-      GBRAIN_CHAT_MODEL: 'anthropic:claude-sonnet-4-6',
-    });
-    expect(got.embedding_model).toBe('voyage:voyage-3-large');
-    expect(got.embedding_dimensions).toBe(1024);
-    expect(got.expansion_model).toBe('openai:gpt-5-mini');
-    expect(got.chat_model).toBe('anthropic:claude-sonnet-4-6');
-  });
-
-  test('null config + no env vars → empty seed (Tier-3 detection takes over)', () => {
-    const got = seedAIOptionsFromConfig(null, {});
-    expect(got).toEqual({});
-  });
-
-  test('persisted config wins (loadConfig already merged env when non-null)', () => {
-    const got = seedAIOptionsFromConfig(
-      { engine: 'pglite', embedding_model: 'openai:text-embedding-3-small', embedding_dimensions: 1536 } as any,
-      { GBRAIN_EMBEDDING_MODEL: 'voyage:voyage-3-large' },
-    );
-    expect(got.embedding_model).toBe('openai:text-embedding-3-small');
-    expect(got.embedding_dimensions).toBe(1536);
-  });
-
-  test('embedding_disabled sentinel honored on re-init', () => {
-    const got = seedAIOptionsFromConfig({ engine: 'pglite', embedding_disabled: true } as any, {});
-    expect(got.noEmbedding).toBe(true);
-    expect(got.embedding_model).toBeUndefined();
-  });
-
-  test('non-numeric GBRAIN_EMBEDDING_DIMENSIONS ignored, model still seeds', () => {
-    const got = seedAIOptionsFromConfig(null, {
-      GBRAIN_EMBEDDING_MODEL: 'voyage:voyage-3-large',
-      GBRAIN_EMBEDDING_DIMENSIONS: 'not-a-number',
-    });
-    expect(got.embedding_model).toBe('voyage:voyage-3-large');
-    expect(got.embedding_dimensions).toBeUndefined();
-  });
-});

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);

test/whoami.test.ts

@@ -94,35 +94,6 @@ describe('whoami op contract', () => {
     expect(result.expires_at).toBeNull();
   });
 
-  // #1061: stdio MCP is remote/untrusted by design but has no per-token auth
-  // (local pipe). The stdio dispatch marks ctx.transport='stdio'; whoami
-  // reports it instead of throwing unknown_transport.
-  test('stdio transport (remote=true, no auth, transport marker) reports stdio', async () => {
-    const result = (await whoami.handler(
-      ctxWith({ remote: true, auth: undefined, transport: 'stdio' }),
-      {},
-    )) as any;
-    expect(result.transport).toBe('stdio');
-    expect(result.scopes).toEqual([]);
-  });
-
-  test('stdio marker does not mask real auth (auth still wins)', async () => {
-    const result = (await whoami.handler(
-      ctxWith({
-        remote: true,
-        transport: 'stdio',
-        auth: {
-          token: 'gbrain_at_xxx',
-          clientId: 'gbrain_cl_abc',
-          scopes: ['read'],
-          expiresAt: 1,
-        } as AuthInfo,
-      }),
-      {},
-    )) as any;
-    expect(result.transport).toBe('oauth');
-  });
-
   // Q3: ambiguous transport — fail-closed. The footgun this guards against
   // is a future transport that lands without threading auth, where a buggy
   // caller might trust whoami's output to gate sensitive ops.