chore(brain): touchfiles + TODOS + CHANGELOG for v1.50.0.0

test/helpers/touchfiles.ts: register the two new E2Es in
E2E_TOUCHFILES + E2E_TIERS (both periodic):
  - office-hours-brain-writeback: triggered by resolver / gen-pipeline /
    detection helper / refresh subcommand / office-hours template /
    docs / fixture / test file changes
  - gbrain-roundtrip-local: triggered by resolver / test file changes

TODOS.md: append two P2 follow-ups carried over from the v1.50 plan:
  - Re-verify calibration takes when gbrain v0.42+ ships takes_add and
    BRAIN_CALIBRATION_WRITEBACK flips TRUE
  - Extend brain-writeback E2E to the other 4 planning skills (extract
    makeFakeGbrain to test/helpers/fake-gbrain.ts when second consumer
    arrives)

CHANGELOG.md v1.50.0.0: add a "Save-results path: works under any CLI
when gbrain is on PATH" section that documents the headline:
  - Conditional inclusion at setup-time (zero overhead for non-gbrain
    users, ~250 tokens with gbrain)
  - Wiring symmetry fix (5 of 5 planning skills now write a page)
  - Token cost table comparing detection states
  - Test coverage map (resolver unit + override mechanism + fake-CLI
    agent obedience + real PGLite round-trip)
  - Why remote routing isn't tested here (gbrain's contract)

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

test/helpers/touchfiles.ts

@@ -378,6 +378,35 @@ export const E2E_TOUCHFILES: Record<string, string[]> = {
   // /spec end-to-end via PTY — exercises the full Phase 1→5 pipeline
   // including --execute spawn. Periodic-tier — paid + non-deterministic.
   'spec-execute':     ['spec/**', 'test/skill-e2e-spec-execute.test.ts'],
+
+  // /office-hours brain-writeback path under fake gbrain CLI (v1.50.0.0
+  // T7). Drives /office-hours with a regenerated SKILL.md that has the
+  // compressed GBRAIN_SAVE_RESULTS block + a fake gbrain on PATH; asserts
+  // the agent calls `gbrain put office-hours/<slug>` with valid YAML
+  // frontmatter. Touched by anything that changes resolver output, gen
+  // pipeline, detection helper, refresh subcommand, or the on-demand
+  // docs the resolver points to.
+  'office-hours-brain-writeback': [
+    'scripts/resolvers/gbrain.ts',
+    'scripts/gen-skill-docs.ts',
+    'bin/gstack-gbrain-detect',
+    'bin/gstack-config',
+    'office-hours/SKILL.md.tmpl',
+    'docs/gbrain-write-surfaces.md',
+    'test/fixtures/office-hours-brain-writeback/**',
+    'test/skill-e2e-office-hours-brain-writeback.test.ts',
+  ],
+
+  // gbrain CLI real round-trip against a local PGLite store (v1.50.0.0
+  // T11). Proves the gbrain CLI persistence contract gstack relies on —
+  // a `gbrain put` followed by `gbrain get` returns the body. Skips if
+  // VOYAGE_API_KEY is unset OR gbrain CLI not on PATH. Touched by the
+  // resolver (which emits the CLI shape) and the test itself.
+  'gbrain-roundtrip-local': [
+    'scripts/resolvers/gbrain.ts',
+    'test/skill-e2e-gbrain-roundtrip-local.test.ts',
+  ],
+
 };
 
 /**
@@ -425,6 +454,13 @@ export const E2E_TIERS: Record<string, 'gate' | 'periodic'> = {
 
   // Office Hours
   'office-hours-spec-review': 'gate',
+  // Brain-writeback E2E — periodic per cost (claude -p) + non-deterministic
+  // (model interprets the gbrain instruction). Matches nearby
+  // setup-gbrain-path4-* tier classification.
+  'office-hours-brain-writeback': 'periodic',
+  // GBrain CLI round-trip — periodic per Voyage embedding cost (~$0.001/run)
+  // and external-API-dependency (skips cleanly if VOYAGE_API_KEY unset).
+  'gbrain-roundtrip-local': 'periodic',
   'office-hours-forcing-energy': 'gate',       // V1.1 mode-posture regression gate (Sonnet generator)
   // 'office-hours-builder-wildness' retiered to periodic in v1.32 contributor
   // wave: this is an LLM-judge creativity score (axis_a ≥4 on a "wildness"