114e971518
Task 6 of the slice plan. Adds the initial database surface: - m001_initial: notes (with v0.2 columns user_intent, intent_prompted_at, title_edited_by_user, summary_edited_by_user), tags, note_tags (with source ai/user), media, pending_jobs. - migrations/index: forward-only PRAGMA user_version runner that applies pending migrations inside a single transaction. - db/index: openDb() that opens better-sqlite3, enables WAL + foreign_keys, then runs migrations. - migrations.test: schema columns are present at v1; runMigrations is idempotent. Verification: `npx vitest run tests/unit/migrations.test.ts` 2 passed. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>