Add Force Restart to extension Settings and launcher

launcher.py:
- _kill_port(port): kills any process listening on a port via netstat+powershell (Win) or lsof+kill (Unix)
- cmd_force_restart(): kills PID-tracked server + anything holding port 18925, starts fresh
- 'force_restart' added to command dispatch table

extension:
- FORCE_RESTART_MCP message type in types.ts
- background.ts routes FORCE_RESTART_MCP -> 'force_restart' native message
- useMcpLauncher: forceRestart() action
- MCP Bridge UI: amber "↺ Restart" button visible when launcher is installed
  Kills stale/competing servers on port 18925 and starts a clean one

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: drknowhow

extension/src/background.ts

@@ -617,11 +617,13 @@ onMessage((message: Message, _sender, sendResponse) => {
     case 'STOP_MCP_SERVER':
     case 'MCP_LAUNCHER_STATUS':
     case 'REMOVE_MCP_LAUNCHER':
-    case 'INSTALL_LOCAL_MCP': {
+    case 'INSTALL_LOCAL_MCP':
+    case 'FORCE_RESTART_MCP': {
       const cmd = type === 'LAUNCH_MCP_SERVER'  ? 'start'
                 : type === 'STOP_MCP_SERVER'    ? 'stop'
                 : type === 'REMOVE_MCP_LAUNCHER'? 'uninstall'
                 : type === 'INSTALL_LOCAL_MCP'  ? 'install_local'
+                : type === 'FORCE_RESTART_MCP'  ? 'force_restart'
                 :                                 'status';
       const nativePayload = type === 'INSTALL_LOCAL_MCP'
         ? { command: cmd, payload: { project_path: (payload as Record<string, string>).projectPath } }

extension/src/components/SettingsPanel.tsx

@@ -145,7 +145,16 @@ function useMcpLauncher() {
     } finally { setBusy(false); }
   };
 
-  return { status, busy, start, stop, remove, refresh: query };
+  const forceRestart = async () => {
+    setBusy(true);
+    try {
+      const res = await chrome.runtime.sendMessage({ type: 'FORCE_RESTART_MCP' });
+      if (res?.notInstalled) persist('not_installed');
+      else if (res?.success) persist('running');
+    } finally { setBusy(false); }
+  };
+
+  return { status, busy, start, stop, remove, forceRestart, refresh: query };
 }
 
 // ── MCP Server Card ──
@@ -574,7 +583,7 @@ function AiToolsSection() {
 
 export default function SettingsPanel() {
   const { status: wsStatus, refresh: refreshWs, reconnect: reconnectWs } = useMcpStatus();
-  const { status: launchStatus, busy, start, stop, remove, refresh: refreshLauncher } = useMcpLauncher();
+  const { status: launchStatus, busy, start, stop, remove, forceRestart, refresh: refreshLauncher } = useMcpLauncher();
   const [extId] = useState(() => chrome.runtime.id);
   const [idCopied, setIdCopied] = useState(false);
 
@@ -679,6 +688,16 @@ export default function SettingsPanel() {
                     </>
                   )
                 )}
+                {launchStatus !== 'not_installed' && launchStatus !== 'unknown' && (
+                  <button
+                    onClick={() => { forceRestart(); setTimeout(() => { refreshWs(); refreshLauncher(); }, 2000); }}
+                    disabled={busy}
+                    className="px-2 py-1 text-[10px] font-semibold text-amber-600 hover:text-amber-700 border border-amber-200 bg-amber-50 hover:bg-amber-100 disabled:opacity-40 rounded transition-colors"
+                    title="Kill any stale server on port 18925 and start fresh"
+                  >
+                    {busy ? '…' : '↺ Restart'}
+                  </button>
+                )}
                 <button
                   onClick={() => { refreshWs(); refreshLauncher(); }}
                   className="p-1 text-gray-400 hover:text-gray-600 transition-colors"

extension/src/types.ts

@@ -76,6 +76,7 @@ export type MessageType =
   | 'MCP_LAUNCHER_STATUS'
   | 'REMOVE_MCP_LAUNCHER'
   | 'INSTALL_LOCAL_MCP'
+  | 'FORCE_RESTART_MCP'
   // ── API (MCP WebSocket bridge) ──
   | 'API_NAVIGATE'
   | 'API_SCREENSHOT'

mcp-server/launcher.py

@@ -143,6 +143,54 @@ def cmd_install_local(payload: dict) -> dict:
         return {'success': False, 'error': str(e)}
 
 
+def _kill_port(port: int) -> list[int]:
+    """Kill any process listening on the given port. Returns list of killed PIDs."""
+    killed = []
+    try:
+        if sys.platform == 'win32':
+            out = subprocess.run(['netstat', '-ano'], capture_output=True, text=True).stdout
+            for line in out.splitlines():
+                if f'127.0.0.1:{port}' in line and 'LISTENING' in line:
+                    pid = int(line.split()[-1])
+                    subprocess.run(
+                        ['powershell', '-Command', f'Stop-Process -Id {pid} -Force -ErrorAction SilentlyContinue'],
+                        capture_output=True,
+                    )
+                    killed.append(pid)
+        else:
+            out = subprocess.run(['lsof', '-ti', f'tcp:{port}'], capture_output=True, text=True).stdout
+            for pid_str in out.strip().splitlines():
+                pid = int(pid_str)
+                os.kill(pid, 9)
+                killed.append(pid)
+    except Exception:
+        pass
+    return killed
+
+
+def cmd_force_restart() -> dict:
+    """Kill every process holding port 18925 (including stale --ws-only servers
+    and any competing MCP instances) then start a fresh --ws-only server."""
+    import time
+
+    # Kill the PID-tracked server if any
+    pid = read_pid()
+    if pid:
+        _kill(pid)
+        if os.path.exists(PID_FILE):
+            os.unlink(PID_FILE)
+
+    # Force-kill anything else holding the port
+    killed = _kill_port(18925)
+
+    # Brief pause for the port to release
+    if killed:
+        time.sleep(0.8)
+
+    # Start fresh
+    return cmd_start()
+
+
 def cmd_uninstall() -> dict:
     """Remove the native host registration and generated files."""
     HOST_NAME = 'com.sentinel.launcher'
@@ -184,11 +232,12 @@ def main() -> None:
     cmd = msg.get('command', '')
     payload = msg.get('payload', {})
     handlers = {
-        'start':         lambda: cmd_start(),
-        'stop':          lambda: cmd_stop(),
-        'status':        lambda: cmd_status(),
-        'uninstall':     lambda: cmd_uninstall(),
-        'install_local': lambda: cmd_install_local(payload),
+        'start':          lambda: cmd_start(),
+        'stop':           lambda: cmd_stop(),
+        'status':         lambda: cmd_status(),
+        'force_restart':  lambda: cmd_force_restart(),
+        'uninstall':      lambda: cmd_uninstall(),
+        'install_local':  lambda: cmd_install_local(payload),
     }
     handler = handlers.get(cmd)
     if handler: