Integrate local Voice platform into dev

[MarcusJRLee]

Scope

Rollup integration point for the complete local Voice platform. This branch adds no work beyond the reviewed stack and points at exact tip 3d7c4c0.

Implementation PR order: #3, #4, #5, #6, #7, #8, #9, #10, #11, #12, #13, #15, #14, #16, #17, #18, #19, #20, #21, #22, #23, #24, #25, #26, #27, #28, #29, #30, #31, #32, #33.

Final verification

• macOS, iOS, and Rust verification suites pass at the exact tip.
• 513 Swift tests across 76 suites pass.
• 34 Rust tests pass.
• SQLite contention and 10,000-transition latency checks pass; p99 is 0.020 ms.
• Signed macOS app installed and launched from Applications with the expected Team identifier.
• Signed iOS device build validates with the expected Team identifier and app, keyboard, and widget extension boundaries.
• PR iOS: finish system-surface capture #33 Verify is green.

Integration policy

The active dev ruleset requires Verify and CodeQL, allows squash merge only, and has no bypass actors. GitHub currently emits Verify but no CodeQL context for dev-targeted PRs. This PR deliberately preserves that protection and records the complete stack without an administrative bypass.

main, release metadata, tags, and releases are unchanged.

Remaining external verification

Physical iPhone installation reached the paired device but the free development profile already contains its maximum three unrelated apps. No apps were removed. Lock Screen, Action button, Siri, and locked-device stop behavior therefore remain physical-device verification items.