feat(desktop): add Computer History - #3193

Summary

• vendor the MIT clean-room macOS interaction-event collector as a packaged Swift helper
• add main-process lifecycle, privacy, storage, capability, and IPC authority
• add a first-class workbar timeline with explicit reduced-context insertion into the Composer
• add focused Core, Swift, main-process, responsive, and real Electron coverage

Why

Maka has Daily Review, but it does not provide an app-level local activity timeline. This adds an opt-in event-stream history without screenshots or audio, keeps raw events local, and lets users deliberately attach a privacy-reduced slice to a task.

Privacy and safety

• disabled by default
• typed-text capture disabled by default
• secure fields and private-browsing windows suppressed
• raw event files remain behind main-process IPC
• reduced context enters the Composer only after an explicit user action
• observed window metadata is bounded, sanitized, and wrapped as untrusted data

Validation

• Desktop tests: 908/908
• Core tests: 553/553
• Swift tests: 12/12
• Desktop typecheck and Biome check
• production resources/main/preload/overlay/renderer build
• real Electron Computer History E2E, including 375px responsive layout

Design notes

See docs/computer-history-integration.md for the product boundary, ownership model, privacy defaults, packaging, and follow-up work.