feat(brain): brain-aware planning resolvers + 3 new placeholders (T4)

scripts/resolvers/gbrain.ts adds:
  - generateBrainPreflight(ctx)       — emits per-skill ## Brain Context
                                        block + bash that loads digests via
                                        gstack-brain-cache get (one call per
                                        digest). Per-skill subset comes from
                                        SKILL_DIGEST_SUBSETS (single source).
  - generateBrainCacheRefresh(ctx)    — at-skill-end background refresh hook;
                                        non-blocking; warms cache for next run.
  - generateBrainWriteBack(ctx)       — Phase 2 / E5 calibration write-back
                                        with per-skill weight. Gated on
                                        personal trust policy + the
                                        BRAIN_CALIBRATION_WRITEBACK flag.
                                        Includes invalidation bash that busts
                                        affected digests after the write.

scripts/resolvers/index.ts registers three new placeholders:
  {{BRAIN_PREFLIGHT}}, {{BRAIN_CACHE_REFRESH}}, {{BRAIN_WRITE_BACK}}

All three resolvers return empty string for skills not in
SKILL_DIGEST_SUBSETS (defensive — skill template authors can drop the
placeholders into non-preflight skills with zero effect).

D9 privacy is mentioned in the rendered preflight prose so the agent
knows to expect filtered salience.
D11 codex tension: write-back gates on brain_trust_policy@<hash> being
personal — shared brains skip write-back to avoid polluting team
calibration profile.

test/brain-preflight.test.ts: 19 tests covering subset rendering,
non-preflight skill gating, cross-project vs per-project --project flag
emission, weight injection per skill, BRAIN_CALIBRATION_WRITEBACK flag
mention, and registration in RESOLVERS map.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/resolvers/gbrain.ts

@@ -6,11 +6,25 @@
  *
  * These resolvers are suppressed on hosts that don't support brain features
  * (via suppressedResolvers in each host config). For those hosts,
- * {{GBRAIN_CONTEXT_LOAD}} and {{GBRAIN_SAVE_RESULTS}} resolve to empty string.
+ * {{GBRAIN_CONTEXT_LOAD}}, {{GBRAIN_SAVE_RESULTS}}, {{BRAIN_PREFLIGHT}},
+ * {{BRAIN_CACHE_REFRESH}}, and {{BRAIN_WRITE_BACK}} all resolve to empty string.
  *
  * Compatible with GBrain >= v0.10.0 (search CLI, doctor --fast --json, entity enrichment).
+ *
+ * Brain-aware planning (T4 / v1.48 plan): adds three new resolvers powered by
+ * the bin/gstack-brain-cache CLI and scripts/brain-cache-spec.ts. The new
+ * resolvers fire only for the 5 planning skills registered in
+ * SKILL_DIGEST_SUBSETS (office-hours, plan-ceo-review, plan-eng-review,
+ * plan-design-review, plan-devex-review).
  */
 import type { TemplateContext } from './types';
+import {
+  SKILL_DIGEST_SUBSETS,
+  SKILL_CALIBRATION_WEIGHTS,
+  BRAIN_CACHE_ENTITIES,
+  getSkillSubset,
+  getInvalidationTargets,
+} from '../brain-cache-spec';
 
 export function generateGBrainContextLoad(ctx: TemplateContext): string {
   let base = `## Brain Context Load
@@ -79,3 +93,155 @@ Add backlinks to related brain pages if they exist. If GBrain is not available,
 
 After brain operations complete, note in your completion output: how many pages were found in the initial search, how many entities were enriched, and whether any operations were throttled. This helps the user see brain utilization over time.`;
 }
+
+// ────────────────────────────────────────────────────────────────────
+// Brain-aware planning resolvers (T4 / v1.48 plan)
+// ────────────────────────────────────────────────────────────────────
+
+/**
+ * Returns true when this skill is registered for brain preflight. Skills not
+ * in SKILL_DIGEST_SUBSETS get an empty BRAIN_PREFLIGHT block (no behavior).
+ */
+function isPreflightSkill(skillName: string): boolean {
+  return Object.prototype.hasOwnProperty.call(SKILL_DIGEST_SUBSETS, skillName);
+}
+
+/**
+ * Renders the per-skill BRAIN_PREFLIGHT block. The rendered output is a single
+ * bash script that:
+ *   1. Reads each digest file from gstack-brain-cache get (one call per digest)
+ *   2. Falls back to "(brain context unavailable)" on missing
+ *   3. Concatenates outputs into a single ## Brain Context block injected
+ *      into the skill's prompt context
+ *   4. Tells the agent: "use this context to skip already-known questions"
+ *
+ * The cache CLI handles cold-refresh + lock dedup + stale-but-usable
+ * fallback internally. From the resolver's perspective the call is one
+ * shell command per digest.
+ */
+export function generateBrainPreflight(ctx: TemplateContext): string {
+  if (!isPreflightSkill(ctx.skillName)) return '';
+  const subset = getSkillSubset(ctx.skillName);
+  const binDir = ctx.paths.binDir;
+  // Build the bash that loads each digest. Per-skill subset is small (2-5 entries).
+  const loadLines = subset.map((entityName) => {
+    const entity = BRAIN_CACHE_ENTITIES[entityName];
+    if (!entity) return '';
+    const projectFlag = entity.scope === 'per-project' ? '--project "$SLUG"' : '';
+    return `  printf '\\n### %s\\n\\n' "${entityName}"\n  ${binDir}/gstack-brain-cache get ${entityName} ${projectFlag} 2>/dev/null || printf '_(no ${entityName} digest available yet)_\\n'`;
+  }).join('\n');
+
+  return `## Brain Context (preflight)
+
+Before asking any clarifying questions, load the brain's structured context
+for this project. The cache layer handles staleness, refresh, and stale-but-
+usable fallback automatically. Skip questions whose answers are already
+present in the loaded context; ground recommendations in what the brain
+already knows about the user, the product, the goals, and recent decisions.
+
+\`\`\`bash
+eval "$(${binDir}/gstack-slug 2>/dev/null)" 2>/dev/null || true
+{
+  printf '## Brain Context\\n\\n'
+${loadLines}
+} > /tmp/.gstack-brain-context-$$.md 2>/dev/null
+[ -s /tmp/.gstack-brain-context-$$.md ] && cat /tmp/.gstack-brain-context-$$.md
+rm -f /tmp/.gstack-brain-context-$$.md 2>/dev/null || true
+\`\`\`
+
+**How to use this context:**
+- If \`product\` digest names the value prop, target user, or stage — don't re-ask.
+- If \`goals\` digest lists active goals — frame recommendations against them.
+- If \`recent-decisions\` digest names a prior scope/architecture choice — flag if this plan contradicts.
+- If \`user-profile\` digest carries calibration pattern statements ("tends to over-engineer security") — surface them when relevant.
+- If a digest is \`(no X digest available yet)\`, treat that section as cold; ask the user.
+
+**Privacy:** Salience digest is filtered by allowlist (D9 default: \`projects/\`,
+\`gstack/\`, \`concepts/\` only). Personal/family/therapy content never leaks here.
+`;
+}
+
+/**
+ * Renders the at-skill-end background refresh hook. Fires after the skill's
+ * own work completes (telemetry has already logged); kicks any digest whose
+ * age exceeds half its TTL but hasn't yet expired, so the NEXT invocation
+ * gets a fresh cache without paying the cold-miss tax.
+ *
+ * Subordinate to {{TELEMETRY}} — runs after. Doesn't block the user.
+ */
+export function generateBrainCacheRefresh(ctx: TemplateContext): string {
+  if (!isPreflightSkill(ctx.skillName)) return '';
+  const binDir = ctx.paths.binDir;
+  return `## Brain Cache Background Refresh
+
+After the skill's work completes (and telemetry has logged), kick a
+background refresh of any cache digest that's getting close to its TTL.
+This is non-blocking — the user doesn't wait. Next invocation benefits
+from the warm cache.
+
+\`\`\`bash
+eval "$(${binDir}/gstack-slug 2>/dev/null)" 2>/dev/null || true
+(${binDir}/gstack-brain-cache refresh --project "$SLUG" 2>/dev/null &) || true
+\`\`\`
+`;
+}
+
+/**
+ * Renders the calibration write-back block. ONLY emits when the skill makes
+ * typed decisions worth a kind=bet take AND the brain trust policy is
+ * personal. Phase 2 / E5 cross-skill calibration.
+ *
+ * Gated behind BRAIN_CALIBRATION_WRITEBACK feature flag in the resolver
+ * output — the flag stays false until upstream gbrain ships takes_add MCP
+ * op (T8). When the flag flips, the existing skill templates pick up the
+ * write-back behavior without any template changes.
+ */
+export function generateBrainWriteBack(ctx: TemplateContext): string {
+  if (!isPreflightSkill(ctx.skillName)) return '';
+  const weight = SKILL_CALIBRATION_WEIGHTS[ctx.skillName];
+  if (weight == null) return '';
+  // List the cache digests this skill's writes should invalidate. Multiple
+  // skills write to multiple entities; the invalidation map captures this.
+  const invalidatesEntities = getInvalidationTargets(`/${ctx.skillName}`);
+  const invalidateBash = invalidatesEntities
+    .map((e) => `  ${ctx.paths.binDir}/gstack-brain-cache invalidate ${e} --project "$SLUG" 2>/dev/null || true`)
+    .join('\n');
+
+  return `## Brain Calibration Write-Back (Phase 2 / gated)
+
+When the skill makes a typed prediction worth tracking (scope decision,
+TTHW target, architectural bet, wedge commitment), it MAY write a
+\`kind=bet\` take to the brain so a calibration profile builds over time.
+
+**Gated on two things:**
+1. Brain trust policy for the active endpoint is \`personal\` (check via
+   \`${ctx.paths.binDir}/gstack-config get brain_trust_policy@<endpoint-hash>\`).
+   Shared brains skip write-back to avoid polluting team calibration.
+2. Feature flag \`BRAIN_CALIBRATION_WRITEBACK\` is set (today: false; flips
+   to true when upstream gbrain v0.42+ ships \`takes_add\` MCP op).
+
+When both gates pass, the write-back path uses \`mcp__gbrain__takes_add\`
+to record a take with weight ${weight} (per SKILL_CALIBRATION_WEIGHTS).
+If the MCP op is unavailable, fall back to \`mcp__gbrain__put_page\` with
+a gstack:takes fence block (documented but uglier path).
+
+Mandatory take frontmatter shape:
+\`\`\`yaml
+kind: bet
+holder: <user identity from whoami>
+claim: <one-line prediction the skill is making>
+weight: ${weight}
+since_date: <today's date>
+expected_resolution: <date in 1-3 months depending on skill>
+source_skill: ${ctx.skillName}
+\`\`\`
+
+After write, invalidate the affected digests so the next preflight reflects
+the new state:
+
+\`\`\`bash
+eval "$(${ctx.paths.binDir}/gstack-slug 2>/dev/null)" 2>/dev/null || true
+${invalidateBash || '  # (no per-skill invalidation targets configured)'}
+\`\`\`
+`;
+}

scripts/resolvers/index.ts

@@ -30,7 +30,7 @@ import { generateInvokeSkill } from './composition';
 import { generateReviewArmy } from './review-army';
 import { generateDxFramework } from './dx';
 import { generateModelOverlay } from './model-overlay';
-import { generateGBrainContextLoad, generateGBrainSaveResults } from './gbrain';
+import { generateGBrainContextLoad, generateGBrainSaveResults, generateBrainPreflight, generateBrainCacheRefresh, generateBrainWriteBack } from './gbrain';
 import { generateQuestionPreferenceCheck, generateQuestionLog, generateInlineTuneFeedback } from './question-tuning';
 import { generateMakePdfSetup } from './make-pdf';
 import { generateTasksSectionEmit, generateTasksSectionAggregate } from './tasks-section';
@@ -86,6 +86,9 @@ export const RESOLVERS: Record<string, ResolverValue> = {
   BIN_DIR: (ctx) => ctx.paths.binDir,
   GBRAIN_CONTEXT_LOAD: generateGBrainContextLoad,
   GBRAIN_SAVE_RESULTS: generateGBrainSaveResults,
+  BRAIN_PREFLIGHT: generateBrainPreflight,
+  BRAIN_CACHE_REFRESH: generateBrainCacheRefresh,
+  BRAIN_WRITE_BACK: generateBrainWriteBack,
   QUESTION_PREFERENCE_CHECK: generateQuestionPreferenceCheck,
   QUESTION_LOG: generateQuestionLog,
   INLINE_TUNE_FEEDBACK: generateInlineTuneFeedback,

test/brain-preflight.test.ts

@@ -0,0 +1,166 @@
+/**
+ * Brain-aware planning resolver tests (T4 / T19).
+ *
+ * Verifies the three resolvers in scripts/resolvers/gbrain.ts:
+ *   - generateBrainPreflight — fires for preflight skills, empty for others
+ *   - generateBrainCacheRefresh — same gating
+ *   - generateBrainWriteBack — same gating; only weighted skills emit
+ *
+ * Gate-tier, free, pure import + render.
+ */
+
+import { describe, test, expect } from 'bun:test';
+import {
+  generateBrainPreflight,
+  generateBrainCacheRefresh,
+  generateBrainWriteBack,
+} from '../scripts/resolvers/gbrain';
+import { SKILL_DIGEST_SUBSETS } from '../scripts/brain-cache-spec';
+import { HOST_PATHS } from '../scripts/resolvers/types';
+import type { TemplateContext } from '../scripts/resolvers/types';
+
+function buildCtx(skillName: string): TemplateContext {
+  return {
+    skillName,
+    tmplPath: `/tmp/${skillName}/SKILL.md.tmpl`,
+    host: 'claude',
+    paths: HOST_PATHS.claude,
+  };
+}
+
+describe('generateBrainPreflight', () => {
+  test('emits content for every registered preflight skill', () => {
+    for (const skill of Object.keys(SKILL_DIGEST_SUBSETS)) {
+      const out = generateBrainPreflight(buildCtx(skill));
+      expect(out.length).toBeGreaterThan(0);
+      expect(out).toContain('## Brain Context');
+      expect(out).toContain('gstack-brain-cache get');
+    }
+  });
+
+  test('emits empty string for non-preflight skills (no behavior)', () => {
+    const nonPlanning = ['ship', 'qa', 'investigate', 'retro', 'design-review'];
+    for (const skill of nonPlanning) {
+      expect(generateBrainPreflight(buildCtx(skill))).toBe('');
+    }
+  });
+
+  test('includes per-skill subset entities (office-hours loads 5 digests)', () => {
+    const out = generateBrainPreflight(buildCtx('office-hours'));
+    // office-hours loads: product, goals, user-profile, recent-decisions, salience
+    expect(out).toContain('product');
+    expect(out).toContain('goals');
+    expect(out).toContain('user-profile');
+    expect(out).toContain('recent-decisions');
+    expect(out).toContain('salience');
+  });
+
+  test('plan-eng-review loads minimal subset (2 digests)', () => {
+    const out = generateBrainPreflight(buildCtx('plan-eng-review'));
+    expect(out).toContain('product');
+    expect(out).toContain('recent-decisions');
+    // Should NOT load brand or developer-persona
+    expect(out).not.toContain('gstack-brain-cache get brand');
+    expect(out).not.toContain('gstack-brain-cache get developer-persona');
+  });
+
+  test('mentions D9 salience privacy in the prose (transparency)', () => {
+    const out = generateBrainPreflight(buildCtx('office-hours'));
+    expect(out.toLowerCase()).toContain('privacy');
+    expect(out.toLowerCase()).toContain('allowlist');
+  });
+
+  test('user-profile is loaded WITHOUT --project flag (cross-project)', () => {
+    const out = generateBrainPreflight(buildCtx('office-hours'));
+    const userProfileLine = out.split('\n').find((l) => l.includes('user-profile')) || '';
+    // user-profile is cross-project; the get call should NOT have --project
+    // (the only --project mentions on that line are inside the comment, not in the get call)
+    const getLine = out.split('\n').find((l) => l.includes('gstack-brain-cache get user-profile')) || '';
+    expect(getLine).not.toContain('--project');
+  });
+
+  test('per-project entities are loaded WITH --project "$SLUG"', () => {
+    const out = generateBrainPreflight(buildCtx('plan-eng-review'));
+    expect(out).toContain('--project "$SLUG"');
+  });
+});
+
+describe('generateBrainCacheRefresh', () => {
+  test('emits refresh hook for preflight skills', () => {
+    const out = generateBrainCacheRefresh(buildCtx('plan-ceo-review'));
+    expect(out).toContain('Background Refresh');
+    expect(out).toContain('gstack-brain-cache refresh');
+  });
+
+  test('empty for non-preflight skills', () => {
+    expect(generateBrainCacheRefresh(buildCtx('ship'))).toBe('');
+  });
+
+  test('uses background backgrounding (does not block user)', () => {
+    const out = generateBrainCacheRefresh(buildCtx('plan-ceo-review'));
+    // Background refresh fires the cache refresh in a detached process
+    expect(out).toContain('&');
+  });
+});
+
+describe('generateBrainWriteBack', () => {
+  test('emits write-back block for all 5 weighted preflight skills', () => {
+    for (const skill of Object.keys(SKILL_DIGEST_SUBSETS)) {
+      const out = generateBrainWriteBack(buildCtx(skill));
+      expect(out.length).toBeGreaterThan(0);
+      expect(out).toContain('Calibration Write-Back');
+      expect(out).toContain('BRAIN_CALIBRATION_WRITEBACK');
+    }
+  });
+
+  test('empty for non-preflight skills', () => {
+    expect(generateBrainWriteBack(buildCtx('ship'))).toBe('');
+  });
+
+  test('includes per-skill calibration weight (E5)', () => {
+    const ceo = generateBrainWriteBack(buildCtx('plan-ceo-review'));
+    expect(ceo).toContain('weight: 0.8'); // SKILL_CALIBRATION_WEIGHTS['plan-ceo-review'] = 0.8
+
+    const office = generateBrainWriteBack(buildCtx('office-hours'));
+    expect(office).toContain('weight: 0.9'); // strongest calibration weight
+
+    const design = generateBrainWriteBack(buildCtx('plan-design-review'));
+    expect(design).toContain('weight: 0.5'); // weakest (design predictions are noisy)
+  });
+
+  test('mentions personal trust policy gate (D11 codex tension)', () => {
+    const out = generateBrainWriteBack(buildCtx('plan-ceo-review'));
+    expect(out.toLowerCase()).toContain('personal');
+    expect(out).toContain('brain_trust_policy');
+  });
+
+  test('mentions fallback path when takes_add MCP op unavailable (upstream T8)', () => {
+    const out = generateBrainWriteBack(buildCtx('plan-ceo-review'));
+    expect(out).toContain('put_page');
+    expect(out).toContain('takes');
+  });
+
+  test('emits invalidation bash for affected cache digests', () => {
+    const out = generateBrainWriteBack(buildCtx('plan-ceo-review'));
+    // plan-ceo-review invalidates: product, goals, competitive-intel
+    expect(out).toContain('gstack-brain-cache invalidate');
+  });
+});
+
+describe('resolver registration in index.ts', () => {
+  test('BRAIN_PREFLIGHT placeholder is registered', async () => {
+    const { RESOLVERS } = await import('../scripts/resolvers/index');
+    expect(RESOLVERS.BRAIN_PREFLIGHT).toBeDefined();
+    expect(typeof RESOLVERS.BRAIN_PREFLIGHT).toBe('function');
+  });
+
+  test('BRAIN_CACHE_REFRESH placeholder is registered', async () => {
+    const { RESOLVERS } = await import('../scripts/resolvers/index');
+    expect(RESOLVERS.BRAIN_CACHE_REFRESH).toBeDefined();
+  });
+
+  test('BRAIN_WRITE_BACK placeholder is registered', async () => {
+    const { RESOLVERS } = await import('../scripts/resolvers/index');
+    expect(RESOLVERS.BRAIN_WRITE_BACK).toBeDefined();
+  });
+});