Add Phase 0 test harness (vitest + ESLint) and fix build config

- Add vitest unit tests for Zustand app store state transitions (6 tests)
- Add mock speech-engine WebSocket protocol integration test (spawns server.py --mock on a free port)
- Add ESLint 10 flat config with typescript-eslint; add typecheck/lint/test scripts to package.json
- Fix pre-existing tsc -b breakage via noEmit in tsconfig.node.json; add dedicated tsconfig.tests.json project for Node-side tests
- Track src-tauri/Cargo.lock for reproducible Rust builds; enable protocol-asset Tauri feature
- Ignore generated artifacts (*.tsbuildinfo, src-tauri/gen/, emitted vite.config.js/.d.ts); remove stale emitted vite config copies
- Update AGENTS.md agent guide (demo scope lock, roadmap, verification commands)
- Add HANDOFF.md documenting Phase 0 state and remaining steps for the next agent

Wireframes/Desktop/MeetVault-Desktop-Demo/vitest.config.ts

@@ -0,0 +1,11 @@
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  test: {
+    environment: 'node',
+    setupFiles: ['./src/test/setup.ts'],
+    include: ['src/**/*.test.{ts,tsx}', 'tests/**/*.test.{ts,tsx}'],
+    testTimeout: 30_000,
+    hookTimeout: 60_000,
+  },
+});