Adds two foundational modules that apply-migrations (Lane A-4), the
v0.11.0 orchestrator (Lane C-1), and the stopgap script (Lane C-4) all
depend on.
- src/core/preferences.ts: atomic-write ~/.gbrain/preferences.json
(mktemp + rename, 0o600, forward-compatible for unknown keys) with
validateMinionMode, loadPreferences, savePreferences. Plus
appendCompletedMigration + loadCompletedMigrations for the
~/.gbrain/migrations/completed.jsonl log (tolerates malformed lines).
Uses process.env.HOME || homedir() so $HOME overrides work in CI and
tests; Bun's os.homedir() caches the initial value and ignores later
mutations.
- src/core/cli-util.ts: promptLine(prompt) helper, extracted from
src/commands/init.ts:212-224. Shared so init, apply-migrations, and
the v0.11.0 orchestrator's mode prompt don't each reinvent it.
test/preferences.test.ts: 21 unit tests covering load/save atomicity,
0o600 perms, forward-compat for unknown keys, minion_mode validation,
completed.jsonl JSONL append idempotence, auto-ts population, malformed-
line tolerance in loadCompletedMigrations.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
