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/core/cjk.ts

@@ -20,14 +20,6 @@ export const CJK_SLUG_CHARS = '一-鿿぀-ゟ゠-ヿ가-힯';
 
 export const CJK_RANGES_REGEX = new RegExp(`[${CJK_SLUG_CHARS}]`);
 
-/**
- * Page-slug segment grammar (no anchors): alnum-or-CJK lead char, then
- * alnum/CJK/hyphen continuation. Single source for validatePageSlug
- * (operations.ts), SlugRegistry's SLUG_RE, and the dream-cycle
- * SUMMARY_SLUG_RE so every slug validator shares one grammar (#738).
- */
-export const PAGE_SLUG_SEG = `[a-z0-9${CJK_SLUG_CHARS}][a-z0-9${CJK_SLUG_CHARS}\\-]*`;
-
 export const CJK_SENTENCE_DELIMITERS = ['。', '！', '？']; // 。！？
 export const CJK_CLAUSE_DELIMITERS = ['；', '：', '，', '、']; // ；：，、
 

src/core/cycle/synthesize.ts

@@ -43,11 +43,10 @@ import { serializeMarkdown, serializePageToMarkdown } from '../markdown.ts';
 import type { Page, PageType } from '../types.ts';
 import { validateSourceId } from '../utils.ts';
 import { safeSplitIndex } from '../text-safe.ts';
-import { PAGE_SLUG_SEG } from '../cjk.ts';
 
-// Slug grammar from validatePageSlug — shared via PAGE_SLUG_SEG (#738).
+// Slug regex from validatePageSlug — kept in sync.
 // Used for the orchestrator-written summary index slug.
-const SUMMARY_SLUG_RE = new RegExp(`^${PAGE_SLUG_SEG}(\\/${PAGE_SLUG_SEG})*$`);
+const SUMMARY_SLUG_RE = /^[a-z0-9][a-z0-9\-]*(\/[a-z0-9][a-z0-9\-]*)*$/;
 
 // ── Model context budget (D1, D5, D7, D9) ─────────────────────────────
 

src/core/operations.ts

@@ -25,7 +25,7 @@ import { bumpLastRetrievedAt } from './last-retrieved.ts';
 import { isSearchMode } from './search/mode.ts';
 import { stampEvidence } from './search/evidence.ts';
 import type { SearchResult } from './types.ts';
-import { CJK_SLUG_CHARS, PAGE_SLUG_SEG } from './cjk.ts';
+import { CJK_SLUG_CHARS } from './cjk.ts';
 import * as db from './db.ts';
 import { VERSION } from '../version.ts';
 import {
@@ -162,6 +162,7 @@ export function validatePageSlug(slug: string): void {
   }
   // v0.32.7: CJK ranges (Han / Hiragana / Katakana / Hangul Syllables) allowed
   // in segments. ASCII shape rules (lead char, hyphen continuation) preserved.
+  const PAGE_SLUG_SEG = `[a-z0-9${CJK_SLUG_CHARS}][a-z0-9${CJK_SLUG_CHARS}\\-]*`;
   if (!new RegExp(`^${PAGE_SLUG_SEG}(\\/${PAGE_SLUG_SEG})*$`, 'i').test(slug)) {
     throw new OperationError('invalid_params', `Invalid page_slug: ${slug} (allowed: alphanumeric, CJK, hyphens, forward-slash separated segments)`);
   }

src/core/output/slug-registry.ts

@@ -17,7 +17,6 @@
 
 import type { BrainEngine } from '../engine.ts';
 import type { PageType } from '../types.ts';
-import { PAGE_SLUG_SEG } from '../cjk.ts';
 
 export interface CreateSlugInput {
   /**
@@ -72,9 +71,7 @@ export class SlugRegistryError extends Error {
 // SlugRegistry
 // ---------------------------------------------------------------------------
 
-// Shares the page-slug segment grammar (incl. CJK ranges, #738) with
-// validatePageSlug; keeps this site's dir/name shape (>= 2 segments).
-const SLUG_RE = new RegExp(`^${PAGE_SLUG_SEG}(\\/${PAGE_SLUG_SEG})+$`);
+const SLUG_RE = /^[a-z0-9][a-z0-9\-]*(\/[a-z0-9][a-z0-9\-]*)+$/;
 
 export class SlugRegistry {
   constructor(private engine: BrainEngine) {}

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/cycle-dream-output-root.test.ts

@@ -86,12 +86,6 @@ describe('#2415: loadOutputRoot validation + patterns gather scope', () => {
     expect(await loadOutputRoot(engine)).toBe('wiki');
   });
 
-  test('CJK root passes the slug grammar (#738)', async () => {
-    await engine.setConfig('dream.synthesize.output_root', '知识/笔记');
-    expect(await loadOutputRoot(engine)).toBe('知识/笔记');
-    await engine.setConfig('dream.synthesize.output_root', '');
-  });
-
   test('patterns phase gathers reflections under the configured root', async () => {
     await engine.setConfig('dream.synthesize.output_root', 'notes');
     for (let i = 0; i < 3; i++) {

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/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/writer.test.ts

@@ -203,17 +203,6 @@ describe('SlugRegistry', () => {
     })).rejects.toThrow(SlugRegistryError);
   });
 
-  test('create accepts CJK slugs (#738)', async () => {
-    const reg = new SlugRegistry(engine);
-    const r = await reg.create({
-      desiredSlug: '知识/品牌圣经',
-      displayName: '品牌圣经',
-      type: 'note',
-    });
-    expect(r.slug).toBe('知识/品牌圣经');
-    expect(r.exact).toBe(true);
-  });
-
   test('create throws on invalid slug', async () => {
     const reg = new SlugRegistry(engine);
     await expect(reg.create({