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-tauri/src/lib.rs

@@ -0,0 +1,16 @@
+#[cfg_attr(mobile, tauri::mobile_entry_point)]
+pub fn run() {
+  tauri::Builder::default()
+    .setup(|app| {
+      if cfg!(debug_assertions) {
+        app.handle().plugin(
+          tauri_plugin_log::Builder::default()
+            .level(log::LevelFilter::Info)
+            .build(),
+        )?;
+      }
+      Ok(())
+    })
+    .run(tauri::generate_context!())
+    .expect("error while running tauri application");
+}

v2/src-tauri/src/main.rs

@@ -0,0 +1,6 @@
+// Prevents additional console window on Windows in release, DO NOT REMOVE!!
+#![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
+
+fn main() {
+  bterminal_lib::run();
+}

v2/src-tauri/src/pty.rs

@@ -0,0 +1,2 @@
+// PTY management via portable-pty
+// Phase 2: spawn, resize, I/O streaming to frontend

v2/src-tauri/src/session.rs

@@ -0,0 +1,2 @@
+// Session persistence via rusqlite
+// Phase 4: CRUD, layout save/restore

v2/src-tauri/src/sidecar.rs

@@ -0,0 +1,2 @@
+// Node.js sidecar lifecycle management
+// Phase 3: spawn, restart, health check, stdio NDJSON communication

v2/src-tauri/src/watcher.rs

@@ -0,0 +1,2 @@
+// File watcher for markdown viewer
+// Phase 4: notify crate, debounce, Tauri events