Extend the explicit clipboard library with permission-aware automatic history through reusable Craft APIs.
Acceptance criteria:
- Disabled by default with explicit opt-in and retention control.
- Respect NSPasteboard access behavior and denied states without repeated prompts.
- Exclude concealed, transient and password-manager content.
- Remove clipboard-content debug logging from Craft core.
- Pause, clear and delete controls; history never leaves the device.
- Verify while the palette is hidden and under App Sandbox.
Blocked by: Craft permission and metadata API support.
Sources: https://developer.apple.com/documentation/appkit/nspasteboard/accessbehavior-swift.enum and docs/planning/research.md