fix(agent-runner): spawn built-in MCP server with bun, not node

The Bun migration (c5d0ef8) dropped the in-image tsc build step, so
/app/src/mcp-tools/index.js never exists — only index.ts. The spawn
config in container/agent-runner/src/index.ts still pointed at
index.js and invoked it with `node`, which can't execute TypeScript
anyway. Net effect: every session failed to start the `nanoclaw`
MCP server, so scheduling, send_to_agent, interactive questions,
and self-mod tools were silently absent from the agent's toolset.

Matches entrypoint.sh and src/container-runner.ts, which already
use `exec bun run /app/src/index.ts` for the same reason.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

container/agent-runner/src/index.ts

@@ -73,15 +73,15 @@ async function main(): Promise<void> {
     }
   }
 
-  // MCP server path
+  // MCP server path — bun runs TS directly; no tsc build step in-image.
   const __dirname = path.dirname(fileURLToPath(import.meta.url));
-  const mcpServerPath = path.join(__dirname, 'mcp-tools', 'index.js');
+  const mcpServerPath = path.join(__dirname, 'mcp-tools', 'index.ts');
 
   // Build MCP servers config: nanoclaw built-in + any additional from host
   const mcpServers: Record<string, { command: string; args: string[]; env: Record<string, string> }> = {
     nanoclaw: {
-      command: 'node',
-      args: [mcpServerPath],
+      command: 'bun',
+      args: ['run', mcpServerPath],
       env: {
         SESSION_INBOUND_DB_PATH: process.env.SESSION_INBOUND_DB_PATH || '/workspace/inbound.db',
         SESSION_OUTBOUND_DB_PATH: process.env.SESSION_OUTBOUND_DB_PATH || '/workspace/outbound.db',