Fix media device feedback and set 100 ms playback latency

[kixelated]

Changes

• Use the resolved OS default microphone when no device is explicitly selected, while preserving saved device choices.
• Show a visible message when video is enabled but no camera is found.
• Set watch playback latency to a fixed 100 ms target.

Validation

• Vite production build passed.
• Biome check passed for the three changed files.
• TypeScript check still reports an unrelated error in app/src/tauri/update.ts:59: allowDowngrades is not in the installed CheckOptions type. Validation used a temporary pnpm install because Bun was unavailable here.
• Hardware behavior was not exercised in this environment.

(written by GPT-6)

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No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Advanced

Run ID: 02093af8-1e11-4ef9-8bec-0871a83557e3

📥 Commits

Reviewing files that changed from the base of the PR and between 3c328a1 and e53b85f.

📒 Files selected for processing (3)

• app/src/controls.tsx
• app/src/room/local.ts
• app/src/room/watch.ts

Included review availability: Your plan provides up to 1 included review per hour; 0 remain after this review.

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Walkthrough

Microphone and camera selection now updates the corresponding device setting. Local microphone setup uses the resolved OS default when no microphone device is configured. The camera control shows a “No camera found” status when the camera is enabled, no devices are available, and no media source exists. Watch synchronization now uses a fixed 100-millisecond latency value.

Priority: ➖ Normal

Merge Risk: ⚪ Minimal · up to e53b8

No verified merge-blocking behavior remains in the reviewed changes.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 2 functions across 3 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main changes: media-device handling and fixed 100 ms playback latency.
Description check	✅ Passed	The description covers the media-device changes, playback latency, and validation results. It is relevant to the changeset.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

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