v1.40.0.0 fix wave: gbrain sync hardening (8 community PRs + migration) (#1547)

* fix(gbrain-sync): fold hostname into code-source id hash + migration (#1414)

Cherry-picked from #1468 by 0xDevNinja and extended with the
hostname-fold migration that codex review surfaced.

Pre-fix `deriveCodeSourceId` hashed the absolute repo path alone, so two
machines with identical home-dir layouts (chezmoi-managed dotfiles,
ansible-provisioned VMs) derived the same id and clobbered each other's
`local_path` in a federated brain. Last-writer-wins, with cryptic "Not a
git repository" errors on the loser.

Hash key is now `\${hostname}::\${path}`. Conductor worktrees on a single
host stay distinct (path entropy unchanged within a host); cross-machine
federations stop colliding.

Migration (D1=B + codex refinements): every existing user has a
pre-#1468 path-only-hash source id in their brain that no longer matches
what `deriveCodeSourceId` produces. Without migration, the next sync
registers a fresh source and orphans the old one. This commit adds:

- \`derivePathOnlyHashLegacyId\` — separate helper for the pre-#1468 form.
  Distinct from \`deriveLegacyCodeSourceId\` (pre-pathhash v1.x form);
  both probes run.

- \`planHostnameFoldMigration\` — feature-checks \`gbrain sources rename
  <old> <new>\` (exact argument shape, not just \`--help\`), gates on
  path-drift (skip migration if old source's \`local_path\` differs from
  current repo root), and falls back to register-new + sync-OK +
  remove-old when rename is unsupported. As of gbrain 0.35.0.0 the
  rename subcommand does not exist, so users go through the cleanup
  path; the rename path stays dormant until gbrain ships it.

- \`removeOrphanedSource\` — called only AFTER new-source sync verifies
  page_count > 0. Closes the data-loss window codex flagged where
  "register new, remove old before sync" can wipe pages if sync fails.

- \`sourceLocalPath\` — looks up a source's \`local_path\` from
  \`gbrain sources list --json\` for the drift gate.

- Helpers accept an optional \`env\` parameter so tests can inject a
  gbrain shim via PATH without process-wide PATH mutation (Bun's
  spawnSync doesn't pick up runtime PATH changes). Pre-positions for
  commit 4's centralized gbrain-exec helper.

- \`if (import.meta.main)\` guard around \`main()\` so the helpers can be
  imported for in-process unit tests.

Tests cover: pure derivation, ids-match degenerate case, no-legacy
short-circuit, path-drift skip path, rename path with shim, cleanup
fallback when rename unsupported, cleanup fallback when rename call
itself fails, source-lookup happy/missing/error paths.

\`GSTACK_HOSTNAME\` env var is a test-only knob; production uses
\`os.hostname()\`.

Fixes #1414

Co-Authored-By: Claude <noreply@anthropic.com>

* fix(gbrain-sync): cut source-id slugs on hyphen boundaries (+ #1357)

Cherry-picked from #1481 by drummerms and extended with the explicit
HTTPS-remote regression case for #1357 (decision D2=A).

`constrainSourceId` truncated the slug with `slug.slice(-tailBudget)`,
which cut mid-word when the boundary fell inside a token. For a repo
where the combined `prefix-org-repo-pathhash` exceeded 32 chars, this
produced embarrassing artifacts like `gstack-code-kill-270c0001-c32152`
(from `drummerms-av-sow-wiz-skill-270c0001`).

Two changes carried from #1481, adapted for the #1468 hostpathhash:

1. `constrainSourceId` now walks hyphen-separated tokens from the right,
   accumulating whole tokens until adding the next would exceed
   `tailBudget`. When no token fits, falls through to the existing
   `${prefix}-${hash}` form.

2. `deriveCodeSourceId` now retries with `repo-only-hostpathhash`
   (dropping the org segment) when the full `org-repo-hostpathhash`
   triggers truncation. Keeps the repo name readable when it fits at all.

Plus a new test asserting the source id is period-free for the exact
HTTPS-with-.git remote shape from #1357 (`https://github.com/foo/bar.git`).
canonicalizeRemote strips `.git`; the sanitizer strips any residual
non-alnum. The test closes #1357 by pinning the property.

Closes #1357

Co-Authored-By: Claude <noreply@anthropic.com>

* fix(gbrain): probe CLI without command builtin

* fix(gbrain-sync): centralize gbrain spawn surface + seed DATABASE_URL

Cherry-picked from #1508 by jasshultz, restructured per codex review #4
and #7 to widen scope and centralize the spawn surface.

The bug: gbrain auto-loads .env.local from cwd via dotenv. When
/sync-gbrain runs inside a Next.js / Prisma / Rails project whose
.env.local defines its own DATABASE_URL (pointing at the app's local
DB), gbrain reads that value instead of its own
~/.gbrain/config.json — auth fails, code + memory stages crash.

This commit:

- Adds lib/gbrain-exec.ts: buildGbrainEnv, spawnGbrain, execGbrainJson,
  execGbrainText, spawnGbrainAsync (the last one for memory-ingest's
  streaming gbrain import call). buildGbrainEnv seeds DATABASE_URL from
  ${GBRAIN_HOME:-$HOME/.gbrain}/config.json, returns a fresh env object
  (never the caller's by identity — codex review #11), and honors the
  GSTACK_RESPECT_ENV_DATABASE_URL=1 escape hatch.

- Routes every gbrain spawn in bin/gstack-gbrain-sync.ts and
  bin/gstack-memory-ingest.ts through the helpers. Both files now own
  zero direct spawnSync("gbrain"|spawn("gbrain"|execFileSync("gbrain"
  call sites.

- Threads buildGbrainEnv into the spawnSync("bun", [memory-ingest], ...)
  grandchild in runMemoryIngest (codex review #7). Without this, the
  parent fix is half-baked — the bun child inherits a clean env but
  needs DATABASE_URL pre-seeded too. spawnGbrainAsync inside
  memory-ingest provides defense in depth for standalone invocations.

- Adds GBRAIN_HOME support — aligns with detectEngineTier (already
  honors GBRAIN_HOME) so all gstack-side gbrain calls agree on which
  config file matters. Resolves baseEnv.HOME first, then homedir(), so
  test injection works without process-wide HOME mutation.

- Adds test/build-gbrain-env.test.ts: 10 unit tests covering all five
  env-seeding branches (seed from config / override caller /
  GSTACK_RESPECT escape hatch / missing config / unparseable config /
  no database_url field / GBRAIN_HOME path / object-identity guard /
  unrelated-vars preservation / idempotent-when-matches).

- Adds test/gbrain-exec-invariant.test.ts: static-source check that
  greps both bin/gstack-gbrain-sync.ts and bin/gstack-memory-ingest.ts
  for direct spawnSync("gbrain"|spawn("gbrain"|execFileSync("gbrain"|
  execSync(...gbrain matches and fails the build if any are found.
  Refactor-proof against future contributors adding a new gbrain spawn
  without env threading.

The invariant is intentionally narrow — only the two files where the
DATABASE_URL bug actually hurts users are guarded. Migrating the
spawn sites in lib/gbrain-local-status.ts, lib/gstack-memory-helpers.ts,
and bin/gstack-brain-context-load.ts is a follow-up.

Co-Authored-By: Jason Shultz <jasshultz@gmail.com>
Co-Authored-By: Claude <noreply@anthropic.com>

* fix(gbrain-sync): add .gbrain-source to consumer repo .gitignore (#1384)

The v1.29.0.0 changelog promised .gbrain-source would be added to the
consuming repo's .gitignore so the per-worktree pin stays local, but the
change actually only added it to gstack's own .gitignore. Without the
consumer-side entry, the pin gets committed and Conductor sibling
worktrees of the same repo + branch step on each other's pin every time
anyone commits.

Add ensureGbrainSourceGitignored after a successful gbrain sources
attach in runCodeImport. Idempotent on repeat runs (line-trim match),
creates .gitignore if missing, logs a warning and continues on
permission errors so a read-only checkout doesn't fail the sync.

Gate the top-level main() call behind import.meta.main so tests can
import the helper without triggering a full sync run on module load.

Tests in test/gbrain-source-gitignore.test.ts cover: create-when-missing,
append-without-trailing-newline, append-with-trailing-newline,
idempotent on repeat, recognize whitespace-surrounded entry, no-throw
on read-only file. 6 pass.

* fix(gbrain-sources): bump gbrain sources list --json timeout 10s → 30s

Supabase free-tier cold-starts can push `gbrain sources list --json` past
10s (observed 14.5s in the wild), causing probeSource() to throw ETIMEDOUT
during /sync-gbrain code stage even though the underlying CLI was healthy.
Matches the 30s ceiling already used by `sources add` / `sources remove`
in the same file.

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

* fix(brain-allowlist): sync project-root eng-review-test-plan artifacts (#1452)

Cherry-picked from #1465 by genisis0x and extended with the v1.40.0.0
upgrade migration that codex review #5 surfaced.

#1465 alone only patches bin/gstack-artifacts-init, which means fresh
installs and re-inits pick up the new pattern. But existing users who
already ran v1.38.1.0 have a `.migrations/v1.38.1.0.done` marker — that
migration won't re-run no matter what we change. So their installed
`.brain-allowlist`, `.brain-privacy-map.json`, and `.gitattributes` stay
without the new pattern, and `/plan-eng-review` artifacts continue to
silently drop out of their federation queue.

This commit:

- bin/gstack-artifacts-init: adds projects/*/*-eng-review-test-plan-*.md
  to the three managed blocks. v1.38.1.0 covered design + test-plan; this
  completes the set for /plan-eng-review.

- gstack-upgrade/migrations/v1.40.0.0.sh: targeted in-place repair for
  existing installs. Same idempotent jq-based shape as v1.38.1.0. Adds
  the new pattern to .brain-allowlist (before the USER ADDITIONS marker),
  .brain-privacy-map.json (as class=artifact), and .gitattributes (as
  merge=union). NEVER commits + pushes — the user controls when the
  patches ship to their federated artifacts repo.

- test/artifacts-init-migration.test.ts: 5 new tests covering the
  v1.40.0.0 migration applied on top of a post-v1.38.1.0 state, jq
  patching, gitattributes append, idempotent re-run, and done-marker
  write when files are missing entirely.

Co-Authored-By: Claude <noreply@anthropic.com>

* fix(gbrain-install): skip postinstall on Windows MSYS/MINGW + post-install probe

Cherry-picked from #1487 by genisis0x and extended with the post-install
subcommand probe per T6 / codex review #19.

`bun install` in $INSTALL_DIR fails on Windows MSYS/MINGW/Cygwin shells
because gbrain's native postinstall script mis-parses path arguments
and aborts with a non-zero exit, breaking gstack-gbrain-install for
Windows users running git-bash/MSYS2. The package installs cleanly
without scripts.

This commit:

- Adds Windows shell detection via `uname -s` matching
  MINGW*/MSYS*/CYGWIN*/Windows_NT (#1487's case statement already covers
  all four — codex review #18 confirmed MINGW* is included). Windows
  paths get `bun install --ignore-scripts`; macOS and Linux unchanged.

- Adds a post-install probe of `gbrain sources --help`. `gbrain --version`
  already runs (D19 PATH-shadowing validation), but version success
  doesn't prove the subcommand surface is reachable — and
  `--ignore-scripts` may have skipped artifacts that subcommands need.
  Probe failure logs a clear warning (with Windows-specific remediation
  pointing at re-running `bun install` outside MSYS) but does NOT exit
  non-zero; users may still get value from gbrain even if the probe
  fails transiently.

Refs #1271

Co-Authored-By: Claude <noreply@anthropic.com>

* chore: v1.40.0.0 — gbrain sync hardening wave

Bumps VERSION 1.39.2.0 → 1.40.0.0 (MINOR — substantial gbrain capability
hardening across sync pipeline, install path, federation allowlist;
~600 net LOC added across 8 community PRs + plan-review refinements).

CHANGELOG entry follows the release-summary format: two-line headline,
lead paragraph, "numbers that matter" with before/after table across 8
user-visible surfaces, "what this means for builders" closer, itemized
Added/Changed/Fixed/NOT fixed/For contributors sections.

Per-commit contributor credits: 0xDevNinja, drummerms, Jayesh Betala,
Jason Shultz, genisis0x. Also names NikhileshNanduri and realcarsonterry
in the wave's "Fixed" section for independent submissions of the
.gbrain-source gitignore bug.

Co-Authored-By: Claude <noreply@anthropic.com>

---------

Co-authored-by: 0xDevNinja <manmit0x@gmail.com>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: drummerms <mike@av2o.com>
Co-authored-by: Jayesh Betala <jayesh.betala7@gmail.com>
Co-authored-by: Jason Shultz <jasshultz@gmail.com>
Co-authored-by: genisis0x <manietdavv@gmail.com>