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/adapters/pty-bridge.ts

@@ -0,0 +1,30 @@
+// PTY Bridge — IPC wrapper for Rust PTY backend
+// Phase 2: terminal spawn, resize, input/output streaming
+
+export interface PtyOptions {
+  shell?: string;
+  cwd?: string;
+  env?: Record<string, string>;
+  cols?: number;
+  rows?: number;
+}
+
+/**
+ * Spawn a new PTY session via Tauri IPC.
+ * Phase 2: implement with @tauri-apps/api invoke
+ */
+export async function spawnPty(_options: PtyOptions): Promise<string> {
+  throw new Error('Not implemented — Phase 2');
+}
+
+export async function writePty(_id: string, _data: string): Promise<void> {
+  throw new Error('Not implemented — Phase 2');
+}
+
+export async function resizePty(_id: string, _cols: number, _rows: number): Promise<void> {
+  throw new Error('Not implemented — Phase 2');
+}
+
+export async function killPty(_id: string): Promise<void> {
+  throw new Error('Not implemented — Phase 2');
+}

v2/src/lib/adapters/sdk-messages.ts

@@ -0,0 +1,25 @@
+// SDK Message Adapter — insulates UI from Claude Agent SDK wire format changes
+// This is the ONLY place that knows SDK internals.
+// Phase 3: full implementation
+
+export interface AgentMessage {
+  id: string;
+  type: 'text' | 'tool_call' | 'tool_result' | 'subagent_spawn' | 'subagent_stop' | 'status' | 'cost' | 'unknown';
+  parentId?: string;
+  content: unknown;
+  timestamp: number;
+}
+
+/**
+ * Adapt a raw SDK message to our internal format.
+ * When SDK changes wire format, only this function needs updating.
+ */
+export function adaptSDKMessage(raw: Record<string, unknown>): AgentMessage {
+  // Phase 3: implement based on actual SDK message types
+  return {
+    id: (raw.id as string) ?? crypto.randomUUID(),
+    type: 'unknown',
+    content: raw,
+    timestamp: Date.now(),
+  };
+}