Add optional local table sound controls

Connect browser-local mute, keyboard volume and a test sample with short original Web Audio cues for public phase/status/turn changes and tagged automatic actions. Audio consumes only projected sequences and public phase identity, with no game actions, private eligibility checks, media requests or saved-game writes. Preferences default off at 35%, survive refresh and synchronize across same-origin tabs.

Silent initial snapshots, stale sequence rejection, batch priority and a 700ms cooldown avoid historical replay and queued bursts. User gestures unlock audio; hidden tabs stay silent. Mute, backgrounding and unmount stop active voices, pending unlocks are cancelled, and unavailable audio remains cosmetic. Existing automatic visual notices and AI pacing remain independent.

Six focused regressions cover cursor consumption, phase priority, room changes, bounded volume and voices, unlock cancellation, disposal, unavailable audio and accessible initial controls. Independent review found a mobile panel overflow; the corrected panel stayed inside the viewport in DOM measurements. Browser controls verified enable/mute, keyboard volume, zero-volume disabling, refresh restoration and cross-tab preference updates. Preferences were restored to off/35%. Physical output and screenshot acceptance remain unverified because screenshot capture timed out. Broader event coverage and final sound design remain unfinished.

Types, lint and 4856 offline tests plus production build pass on the unchanged source fingerprint below. The first broad check found the accessibility linter's semantic-output requirement; the status element was corrected before the final checks. HTTP/AI calibration runs were not repeated for this cosmetic-only change.

All 1,072 saved games, 2,243 seats and original recovery/entry/handover records match the pre-outage backup; SQLite quick-check and foreign keys pass. The responding server and isolated browser seat were reused after the latest outage, without resetting games or creating automation. Mode and publication gates remain closed.

Verified source tree: da84d2cc4ed5b0face56afb034857b85c52708e11d86ff3f1cb3c8abdeee99d0

README.md

@@ -30,6 +30,11 @@ An uncertain saved-kit recovery keeps its exact retry details in memory and prev
 
 Use **Pass your seat to another player** for a voluntary one-time transfer. The private offer lasts 24 hours; acceptance preserves progress and revokes the old owner’s sessions and recovery kits. The recipient uses **Accept a seat handover** on the home page, then creates their own recovery kit. Keep the tab open until acceptance is confirmed; exact private retry details survive refresh in that tab. See [seat handover](docs/SEAT_HANDOVER.md) for cancellation, retry behavior and current limits.
 
+The table header offers optional **Sound effects**, with mute, volume and a test
+sample. Short cues mark phase changes and automatic action notices. Sound starts
+off; preferences stay in your browser. See [table sounds](docs/TABLE_SOUNDS.md)
+for activation, background behavior and prototype limits.
+
 ## Verify changes
 
 Use the [development guide](docs/DEVELOPMENT.md) for architecture, focused tests