test: fix 10 test quality bugs (BUG-058–067) and resolve 115 TS type errors

BUG-058: Unblock prod-build E2E — created tsconfig.build.json excluding
tests from the production build. Added typecheck/typecheck:build scripts.

BUG-059: Harden native E2E — CDP timeout 30→60s with exponential backoff,
config timeouts doubled (test 120s, action 30s, nav 45s, expect 15s).

BUG-060: Add 25 Rust unit tests across commands.rs, ws_proxy.rs,
livekit_proxy.rs, credentials.rs (was zero behavioral tests).

BUG-061/067: Add behavioral assertions to server coverage_boost_test.go —
GracefulStop verifies client count, channel_focus verifies no error sent.

BUG-062: Upgrade low-signal test assertions in livekit-session,
device-manager, channel-controller (no-op checks → state checks).

BUG-063: Consolidate native E2E skip gates into beforeEach blocks
(voice-controls 7→1 skip, channel-navigation 4→1 skip).

BUG-064: Add 9 integration tests for channel CRUD, member lifecycle,
DM open/close, and presence events.

BUG-065: Replace 3 fixed sleeps with condition-based waits in E2E specs.

BUG-066: Verified toast/audio tests already cleaned in prior session.

TypeScript: Fix 115 type errors across 21 test files — add non-null
assertions for strict indexing, fix mock typing (vi.fn<any>()), add
missing fields (color, version, deleted) to test fixtures.

Client/tauri-client/package.json

@@ -5,7 +5,7 @@
   "type": "module",
   "scripts": {
     "dev": "vite",
-    "build": "tsc && vite build",
+    "build": "tsc -p tsconfig.build.json && vite build",
     "preview": "vite preview",
     "tauri": "tauri",
     "test": "vitest run",
@@ -17,6 +17,8 @@
     "test:e2e:ui": "playwright test --ui",
     "test:watch": "vitest",
     "test:coverage": "vitest run --coverage",
+    "typecheck": "tsc --noEmit",
+    "typecheck:build": "tsc -p tsconfig.build.json --noEmit",
     "lint": "eslint src/",
     "lint:fix": "eslint src/ --fix"
   },