v1.39.2.0 feat: GSTACK_* env-shim for Conductor + gbrain/gstack setup docs

[garrytan]

Summary

Three commits land Conductor compatibility for paid-API entry points plus the docs that explain it:

Code

• feat: GSTACK_* env-key shim for Conductor workspaces (506ed6b) — new lib/conductor-env-shim.ts promotes GSTACK_ANTHROPIC_API_KEY / GSTACK_OPENAI_API_KEY to canonical names when canonical is empty. Imported as a side effect from the four TS entry points that hit Anthropic/OpenAI: bin/gstack-gbrain-sync.ts, bin/gstack-model-benchmark, scripts/preflight-agent-sdk.ts, test/helpers/e2e-helpers.ts.
• test: unit coverage for conductor-env-shim (93c8a8a) — refactored the shim to export promoteConductorEnv() so unit tests can manipulate env and call it directly. Four tests cover all three branches (promote, no-overwrite, no-op).

Docs

• docs: gbrain+gstack setup, Conductor env mapping (v1.39.2.0) (6d7dad2) — new sections in USING_GBRAIN_WITH_GSTACK.md (What you get, Path 4 / split-engine, /sync-gbrain workflow, Conductor + GSTACK_* env vars, two troubleshooting entries). New paragraph in CONTRIBUTING.md "Conductor workspaces" naming the shim and the four entry points. VERSION 1.39.1.0 → 1.39.2.0 with full release-summary CHANGELOG entry.

Test Coverage

CODE PATHS
[+] lib/conductor-env-shim.ts
  └── promoteConductorEnv()
      ├── [★★★ TESTED] GSTACK_ANTHROPIC_API_KEY → ANTHROPIC_API_KEY promotion
      ├── [★★★ TESTED] GSTACK_OPENAI_API_KEY → OPENAI_API_KEY promotion
      ├── [★★★ TESTED] canonical already set → no overwrite
      └── [★★★ TESTED] neither set → no-op

COVERAGE: 4/4 paths tested (100%)  |  QUALITY: ★★★:4  |  GAPS: 0

Tests: 387 → 391 (+4 new). Full free suite: 718 pass, 0 fail.

Pre-Landing Review

No issues found. Code surface is tiny: 14 lines of TS in the shim (fully unit-tested), 4 single-line import additions, doc updates. Heavy Codex pass skipped — the 209-line diff is mostly markdown.

Design Review

No frontend files changed — skipped.

Eval Results

No prompt-related files changed — evals skipped.

TODOS

No TODO items completed in this PR (no existing entries match this scope).

Documentation

This PR includes its own documentation as part of the planned release:

• USING_GBRAIN_WITH_GSTACK.md — new "What you get after setup", "Path 4 (remote MCP / split-engine)", "/sync-gbrain workflow", "Conductor + GSTACK_* env vars" sections + env vars table extensions + two troubleshooting entries (silent embedding failure, FILE_TOO_LARGE watermark).
• CONTRIBUTING.md — "Conductor workspaces" section gained a paragraph on the GSTACK_* prefix pattern, the shim file, and the four entry points already wired up.

Coverage map (Diataxis):

• lib/conductor-env-shim.ts: reference ✅ CHANGELOG + CONTRIBUTING + USING_GBRAIN, how-to ✅ Conductor section + contributor checklist, explanation ✅ why-prefix rationale in both docs.
• Path 4 / split-engine (already-shipped feature, newly documented): reference ✅, how-to ✅, explanation ✅.
• /sync-gbrain workflow: reference ✅, how-to ✅ stage breakdown + --skip-failed, explanation ✅ pre-flight gating rationale.

Test plan

• bun test test/skill-validation.test.ts test/gen-skill-docs.test.ts test/conductor-env-shim.test.ts — 718 pass, 0 fail
• Manual verification: /sync-gbrain ran clean in this Conductor workspace with only GSTACK_OPENAI_API_KEY in env — 3294 chunks embedded, gbrain search returned ranked code regions at 0.95 top score
• VERSION bumped, package.json synced, CHANGELOG entry at top of file in reverse-chronological order

🤖 Generated with Claude Code

[github-actions]

E2E Evals: ✅ PASS

0/0 tests passed | $0 total cost | 12 parallel runners

Suite	Result	Status	Cost

---

12x ubicloud-standard-8 (Docker: pre-baked toolchain + deps) | wall clock ≈ slowest suite