refactor: implement per-conversation tmux sessions and command-based MCP tools

This commit implements isolated tmux sessions for each conversation and
refines the terminal MCP tools to use consistent command terminology.

**Per-Conversation Tmux Sessions:**
- Each Session now creates its own Terminal MCP client with conversation ID as tmux session name
- Complete isolation: commands from different conversations don't interfere
- Automatic cleanup: tmux session killed when conversation ends
- Updated getAllTools() to accept custom terminal tools per session
- Session.cleanup() now async to properly await tmux session termination

**Command-Based MCP Tools:**
- Removed old terminal-based tools (list_terminals, create_terminal, etc.)
- Kept only command-based tools (execute_command, list_commands, etc.)
- Updated kill_command to accept multiple command IDs for batch cleanup
- Fixed bug where all commands showed same metadata (working directory, command)
- Added window-specific option storage using set-window-option/show-window-options

**Bug Fixes:**
- Fixed listCommands() showing wrong working directory and command for dead commands
- Stored command metadata as tmux window options for proper retrieval
- Enhanced test to verify multiple commands retain unique metadata

**Testing:**
- Added comprehensive test suite with 26 passing tests
- All tests verify command execution, capture, interaction, and cleanup
- TypeScript: no errors
- Backward compatibility maintained with global singleton fallback

Generated with [Claude Code](https://claude.com/claude-code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

packages/voice-assistant/src/server/agent/llm-openai.ts

@@ -152,8 +152,28 @@ const manualTools = {
 
 /**
  * Get all tools (MCP + manual) for LLM
+ * @param terminalTools - Optional custom terminal tools (per-session). If not provided, uses global singleton.
  */
-export async function getAllTools(): Promise<Record<string, any>> {
+export async function getAllTools(terminalTools?: Record<string, any>): Promise<Record<string, any>> {
+  if (terminalTools) {
+    // Use provided terminal tools (per-session) and merge with Playwright
+    const playwrightClient = await getPlaywrightMcpClient().catch((error) => {
+      console.error("Failed to initialize Playwright MCP:", error);
+      return null;
+    });
+
+    const playwrightTools = playwrightClient
+      ? await playwrightClient.tools()
+      : {};
+
+    return {
+      ...terminalTools,
+      ...playwrightTools,
+      ...manualTools,
+    };
+  }
+
+  // Fallback to global singleton tools
   const mcpTools = await getMcpTools();
   return {
     ...mcpTools,