feat(ios): add local formatting and durable history

[MarcusJRLee]

Outcome

Completes the next I2 vertical slice in the containing iOS app: shared deterministic spoken edits and semantic formatting, commit-before-publish local History, searchable immutable Raw/Edited/Formatted evidence, retained-audio playback, and configurable age/byte/count retention.

History uses actor-owned system SQLite plus protected atomic CAF copies. Startup removes partial, orphaned, and crash-left expired audio. Decoded sessions reject noncanonical audio paths. Neither extension receives model, audio, transcript-history, SQLite, or whisper access.

Verification

• complete repository check passed
• complete iOS unit and UI suite passed
• real pinned whisper transcription passed at RTF 0.0090
• signed physical-device build and Team/extension isolation checks passed
• physical install reached the paired iPhone but Apple rejected it because the free profile already has three unrelated apps installed
• 513 macOS tests, SQLite contention, latency soak, Rust/FFI/model checks, and release-script tests passed

Remaining I2 work

Explicit Style selection and the complete one-time signed-device keyboard journey remain separate focused slices.

[MarcusJRLee]

Integrated into dev through rebase-merged rollup PR #34. This intermediate PR remains preserved as the focused review record for its original slice.