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/svelte.config.js

@@ -0,0 +1,8 @@
+import { vitePreprocess } from '@sveltejs/vite-plugin-svelte'
+
+/** @type {import("@sveltejs/vite-plugin-svelte").SvelteConfig} */
+export default {
+  // Consult https://svelte.dev/docs#compile-time-svelte-preprocess
+  // for more information about preprocessors
+  preprocess: vitePreprocess(),
+}