refactor: remove legacy chat/agent implementations, keep transcript-debug

Remove FloatingTerminal (#1), AgentBar/FloatBubble (#2), and all related
components, composables, types, handlers, routes, and CSS. Clean up orphaned
references in ToolsDropdown, whisperSocket, and claude-hook comments.
Transcript-debug is now the sole chat/agent system.

Deleted: 15 files (~3500 lines)
Edited: 12 files (-717 lines net)

server/routes/claude-hook.ts

@@ -107,7 +107,7 @@ export async function handleClaudeHook(req: Request): Promise<Response | null> {
       console.error('[claude-hook] Failed to forward hook to terminal server:', e)
     }
 
-    // 2. Forward PermissionRequest to /claude-permission so PromptBar WS listener picks it up
+    // 2. Forward PermissionRequest to /claude-permission for hooks approval system
     if (body.hook_event_name === 'PermissionRequest') {
       try {
         await fetch(`http://localhost:${PORT_TERMINAL}/claude-permission`, {
@@ -120,7 +120,7 @@ export async function handleClaudeHook(req: Request): Promise<Response | null> {
       }
     }
 
-    // 3. Derive status and broadcast for backward compat (App.vue/AgentBar.vue)
+    // 3. Derive status and broadcast via WebSocket
     const { status, tool } = deriveStatus(body)
     try {
       await fetch(`http://localhost:${PORT_TERMINAL}/claude-status`, {