grid: add gated ios voice rooms and speaker transcripts

[morajabi]

Grid adds gated iOS voice rooms, background audio and remote screen viewing through the existing shared room service. The Home presence pill and overflow menu both open Grid as a native page, and the menu remains available while the pill is visible. macOS adds manual Start/Stop and explicit transcript continuation into ordinary encrypted threads, with speaker attribution and quiet finalized messages.

Media admission follows accepted session/membership authority. Receiving-device Move preserves call identity, rotates membership and starts muted. Room replacement waits for local media teardown, credential replacement requires a physical shutdown receipt, and revoked or old-login replies cannot restore media. Transcription retains no audio or draft feed and has no automatic restart. Final API writes now settle in per-track provider order, including retries and empty retirement, while capture continues within the existing finite bounds. Stop closes admission immediately; the existing graceful deadline and destructive discard remain intact.

The candidate integrates current published main c8e609f8b, including Chat Info, Files compose, CLI 0.7.16 and the reviewed server performance repair. Snapshot/history admission fences, batched deletion and confirmed-versus-optimistic tail ordering are preserved. Quiet transcript rows remain excluded from unread, notifications and sidebar activity. Additive migrations 0154 (call identity) and 0155 (transcription) are unchanged; MCP migration 0156 follows this candidate during coordinator-owned linear landing.

Validation on final source:

• Worker package: 95 tests, including seven new ordering/Stop/retry/authority regressions; typecheck and lint pass.
• Canonical focused server runner against real local PostgreSQL: 105 tests across seven files, zero failures/skips, including transfer, transcript history/deletion/access, concurrent history snapshots and bot-link admission. Disposable test databases only.
• Aggregate server typing and scoped server lint pass. Generated TypeScript/Swift protocol and Rust proto copy match canonical schemas. Swift frontend parse and Apple source contracts pass; scoped SwiftLint has no errors. Independent gpt-6.1-sol source review has no actionable findings.
• Hosted validation is running on b65554f2d (Apple, server). The prior 2578edd79 iOS and macOS Debug/Release builds succeeded, and the new quiet batched-tail regression passed. InlineKit reported 57 issues identical to published main f49c8fe51 (baseline). This follow-up fixes cold cursor rejection that retried rolled-back metadata, adds real catalog rollback coverage, and updates nine test files for current cold admission, witnessed parent history and contiguous coverage. Swift parse, source contracts and independent Sol review pass; runtime test acceptance awaits the new hosted run. Parent coordinates remain valid with absent bodies; child snapshots cannot create or overwrite parent history.
• Main's performance repair c8e609f8b is incorporated with all five repaired paths identical to its tested 2025c4382 source. Its receipt reports 106 real PostgreSQL tests and 10 benchmark contract tests passing. Reply fanout ceilings remain unchanged; catalog/history allowances explicitly account for reviewed fixed snapshot commands. The prior twelve server budget failures are not represented as current acceptance.

Existing source activation gates are preserved. Physical-device/visual acceptance, intended Linux/native/SFU and selected speech-provider acceptance remain open. This source PR performs no production migration, deployment or activation.