Phase 1 foundation: Tauri shell, Python sidecar, SQLite database

Tauri v2 + Svelte + TypeScript frontend:
- App shell with workspace layout (waveform, transcript, speakers, AI chat)
- Placeholder components for all major UI areas
- Typed stores (project, transcript, playback, AI)
- TypeScript interfaces matching the database schema
- Tauri bridge service with typed invoke wrappers
- svelte-check passes with 0 errors

Rust backend:
- Tauri v2 app entry point with command registration
- SQLite database layer (rusqlite with bundled SQLite)
  - Full schema: projects, media_files, speakers, segments, words,
    ai_outputs, annotations (with indexes)
  - Model structs with serde serialization
  - CRUD queries for projects, speakers, segments, words
  - Segment text editing preserves original text
  - Schema versioning for future migrations
  - 6 tests passing
- Command stubs for project, transcribe, export, AI, settings, system
- App state management

Python sidecar:
- JSON-line IPC protocol (stdin/stdout)
- Message types: IPCMessage, progress, error, ready
- Handler registry with routing and error handling
- Ping/pong handler for connectivity testing
- Service stubs: transcribe, diarize, pipeline, AI, export
- Provider stubs: local (llama-server), OpenAI, Anthropic, LiteLLM
- Hardware detection stubs
- 14 tests passing, ruff clean

Also adds:
- Testing strategy document (docs/TESTING.md)
- Validation script (scripts/validate.sh)
- Updated .gitignore for Svelte, Rust, Python artifacts

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/lib/components/ProgressOverlay.svelte

@@ -0,0 +1,58 @@
+<script lang="ts">
+  interface Props {
+    visible?: boolean;
+    percent?: number;
+    stage?: string;
+    message?: string;
+  }
+
+  let { visible = false, percent = 0, stage = '', message = '' }: Props = $props();
+</script>
+
+{#if visible}
+  <div class="overlay">
+    <div class="progress-card">
+      <h3>{stage}</h3>
+      <div class="bar-track">
+        <div class="bar-fill" style="width: {percent}%"></div>
+      </div>
+      <p>{percent}% — {message}</p>
+    </div>
+  </div>
+{/if}
+
+<style>
+  .overlay {
+    position: fixed;
+    inset: 0;
+    background: rgba(0, 0, 0, 0.7);
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    z-index: 1000;
+  }
+  .progress-card {
+    background: #16213e;
+    padding: 2rem;
+    border-radius: 12px;
+    min-width: 400px;
+    color: #e0e0e0;
+  }
+  h3 { margin: 0 0 1rem; text-transform: capitalize; }
+  .bar-track {
+    height: 8px;
+    background: #0f3460;
+    border-radius: 4px;
+    overflow: hidden;
+  }
+  .bar-fill {
+    height: 100%;
+    background: #e94560;
+    transition: width 0.3s;
+  }
+  p {
+    margin: 0.5rem 0 0;
+    font-size: 0.875rem;
+    color: #999;
+  }
+</style>