feat(v2): scaffold Tauri 2.x + Svelte 5 project (Phase 1)

- Tauri 2.10 + Svelte 5.45 + TypeScript + Vite 7
- Catppuccin Mocha theme with CSS variables and semantic aliases
- CSS Grid layout: sidebar (260px) + workspace, responsive breakpoints
  for ultrawide (3440px+) and narrow (<1200px)
- Component structure: Layout/, Terminal/, Agent/, Markdown/, Sidebar/
- Svelte 5 stores with $state runes: sessions, agents, layout
- SDK message adapter (abstracts Agent SDK wire format)
- PTY bridge (Tauri IPC wrapper, stubbed for Phase 2)
- Node.js sidecar entry point (stdio NDJSON, stubbed for Phase 3)
- Rust modules: pty, sidecar, watcher, session (stubbed)
- Vite dev server on port 9700
- Build verified: binary + .deb + .rpm + AppImage all produced

v2/src/lib/components/Sidebar/SessionList.svelte

@@ -0,0 +1,39 @@
+<script lang="ts">
+  // Phase 4: session CRUD, groups, types
+</script>
+
+<div class="session-list">
+  <div class="header">
+    <h2>Sessions</h2>
+  </div>
+  <div class="empty-state">
+    <p>No sessions yet.</p>
+    <p class="hint">Phase 2 will add terminal sessions.</p>
+  </div>
+</div>
+
+<style>
+  .session-list {
+    padding: 12px;
+  }
+
+  .header h2 {
+    font-size: 14px;
+    font-weight: 600;
+    color: var(--text-primary);
+    margin-bottom: 12px;
+  }
+
+  .empty-state {
+    color: var(--text-muted);
+    font-size: 12px;
+    text-align: center;
+    padding: 24px 0;
+  }
+
+  .hint {
+    margin-top: 4px;
+    font-size: 11px;
+    color: var(--ctp-overlay0);
+  }
+</style>