fix: MCP zombie process cleanup (#714)

Adds:
- scripts/mcp_zombie_cleanup.py — kill orphaned MCP processes
- scripts/mcp_watchdog.py — periodic cleanup daemon

Fixes #714

scripts/mcp_watchdog.py

@@ -0,0 +1,83 @@
+#!/usr/bin/env python3
+"""
+mcp-watchdog — Periodic cleanup of orphaned MCP processes.
+
+Runs as a cron job or daemon to prevent process accumulation.
+
+Usage:
+    python scripts/mcp_watchdog.py              # one-shot check
+    python scripts/mcp_watchdog.py --daemon     # continuous monitoring
+"""
+
+import argparse
+import os
+import subprocess
+import sys
+import time
+
+CHECK_INTERVAL = 300  # 5 minutes
+MAX_MCP_PROCESSES = 10
+MAX_PROCESS_AGE = 3600  # 1 hour
+
+
+def count_mcp_processes() -> int:
+    """Count running MCP processes."""
+    try:
+        result = subprocess.run(
+            ["pgrep", "-f", "mcp_server|morrowind|mcp-serve|fastmcp"],
+            capture_output=True, text=True, timeout=5
+        )
+        if result.returncode == 0:
+            return len([p for p in result.stdout.strip().split("\n") if p])
+    except Exception:
+        pass
+    return 0
+
+
+def cleanup_zombies():
+    """Kill zombie MCP processes."""
+    script = os.path.join(os.path.dirname(__file__), "mcp_zombie_cleanup.py")
+    if os.path.exists(script):
+        subprocess.run(
+            [sys.executable, script, "--kill", "--max-instances", "3"],
+            capture_output=True, timeout=30
+        )
+
+
+def run_check():
+    """Run a single watchdog check."""
+    count = count_mcp_processes()
+    
+    if count > MAX_MCP_PROCESSES:
+        print(f"WARNING: {count} MCP processes (max: {MAX_MCP_PROCESSES})")
+        cleanup_zombies()
+        new_count = count_mcp_processes()
+        print(f"Cleaned up: {count} -> {new_count}")
+    else:
+        print(f"OK: {count} MCP processes")
+
+
+def daemon_loop():
+    """Continuous monitoring."""
+    print(f"Starting MCP watchdog (interval={CHECK_INTERVAL}s, max={MAX_MCP_PROCESSES})")
+    while True:
+        try:
+            run_check()
+        except Exception as e:
+            print(f"Error: {e}")
+        time.sleep(CHECK_INTERVAL)
+
+
+def main():
+    parser = argparse.ArgumentParser(description="MCP process watchdog")
+    parser.add_argument("--daemon", action="store_true", help="Run continuous monitoring")
+    args = parser.parse_args()
+    
+    if args.daemon:
+        daemon_loop()
+    else:
+        run_check()
+
+
+if __name__ == "__main__":
+    main()

scripts/mcp_zombie_cleanup.py

@@ -0,0 +1,210 @@
+#!/usr/bin/env python3
+"""
+mcp-zombie-cleanup — Kill orphaned MCP server processes.
+
+Fix for #714: ~80 zombie morrowind/mcp_server.py processes on Mac.
+
+Usage:
+    python scripts/mcp_zombie_cleanup.py              # dry run
+    python scripts/mcp_zombie_cleanup.py --kill        # kill zombies
+    python scripts/mcp_zombie_cleanup.py --status      # show status
+"""
+
+import argparse
+import os
+import signal
+import subprocess
+import sys
+import time
+from typing import List, Dict
+
+# Patterns that identify MCP server processes
+MCP_PATTERNS = [
+    "mcp_server",
+    "morrowind",
+    "mcp-serve",
+    "mcp_tool",
+    "fastmcp",
+]
+
+# Keep at most this many instances per pattern
+MAX_INSTANCES = 3
+
+# Kill processes older than this (seconds)
+MAX_AGE_SECONDS = 3600  # 1 hour
+
+
+def find_mcp_processes() -> List[Dict]:
+    """Find all MCP-related processes."""
+    processes = []
+    
+    try:
+        # Get all Python processes with command lines
+        result = subprocess.run(
+            ["ps", "aux"],
+            capture_output=True, text=True, timeout=10
+        )
+        
+        for line in result.stdout.splitlines():
+            # Skip header and grep itself
+            if "USER" in line or "grep" in line:
+                continue
+            
+            # Check if this is an MCP process
+            line_lower = line.lower()
+            is_mcp = any(pattern in line_lower for pattern in MCP_PATTERNS)
+            
+            if is_mcp and "python" in line_lower:
+                parts = line.split()
+                if len(parts) >= 11:
+                    try:
+                        user = parts[0]
+                        pid = int(parts[1])
+                        cpu = parts[2]
+                        mem = parts[3]
+                        # VSZ and RSS are parts[4] and parts[5]
+                        rss_kb = int(parts[5]) if parts[5].isdigit() else 0
+                        # Start time is parts[8] or parts[9]
+                        start_time = parts[8]
+                        # Command is everything after
+                        cmd = " ".join(parts[10:])
+                        
+                        processes.append({
+                            "user": user,
+                            "pid": pid,
+                            "cpu": cpu,
+                            "mem": mem,
+                            "rss_kb": rss_kb,
+                            "start_time": start_time,
+                            "cmd": cmd[:200],
+                        })
+                    except (ValueError, IndexError):
+                        continue
+    except Exception as e:
+        print(f"Error finding processes: {e}")
+    
+    return processes
+
+
+def get_process_age(pid: int) -> float:
+    """Get process age in seconds."""
+    try:
+        result = subprocess.run(
+            ["ps", "-o", "etimes=", "-p", str(pid)],
+            capture_output=True, text=True, timeout=5
+        )
+        if result.returncode == 0 and result.stdout.strip():
+            return float(result.stdout.strip())
+    except Exception:
+        pass
+    return 0
+
+
+def kill_process(pid: int, force: bool = False) -> bool:
+    """Kill a process."""
+    try:
+        sig = signal.SIGKILL if force else signal.SIGTERM
+        os.kill(pid, sig)
+        return True
+    except ProcessLookupError:
+        return True  # Already dead
+    except PermissionError:
+        print(f"  Permission denied for PID {pid}")
+        return False
+    except Exception as e:
+        print(f"  Error killing PID {pid}: {e}")
+        return False
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Clean up zombie MCP processes")
+    parser.add_argument("--kill", action="store_true", help="Kill zombie processes")
+    parser.add_argument("--force", action="store_true", help="Use SIGKILL instead of SIGTERM")
+    parser.add_argument("--status", action="store_true", help="Show status only")
+    parser.add_argument("--max-instances", type=int, default=MAX_INSTANCES)
+    parser.add_argument("--max-age", type=int, default=MAX_AGE_SECONDS)
+    args = parser.parse_args()
+    
+    processes = find_mcp_processes()
+    
+    if not processes:
+        print("No MCP processes found.")
+        return 0
+    
+    # Group by pattern
+    groups = {}
+    for p in processes:
+        for pattern in MCP_PATTERNS:
+            if pattern in p["cmd"].lower():
+                if pattern not in groups:
+                    groups[pattern] = []
+                groups[pattern].append(p)
+                break
+    
+    total = len(processes)
+    zombies = []
+    keep = []
+    
+    print(f"Found {total} MCP processes:")
+    print()
+    
+    for pattern, procs in groups.items():
+        # Sort by PID (higher = newer)
+        procs.sort(key=lambda p: p["pid"], reverse=True)
+        
+        print(f"Pattern: {pattern}")
+        print(f"  Count: {len(procs)}")
+        
+        for i, p in enumerate(procs):
+            age = get_process_age(p["pid"])
+            age_str = f"{age/3600:.1f}h" if age > 3600 else f"{age/60:.0f}m"
+            
+            status = "KEEP" if i < args.max_instances else "ZOMBIE"
+            if age > args.max_age:
+                status = "STALE"
+            
+            rss_mb = p["rss_kb"] / 1024
+            
+            print(f"  PID {p['pid']:>6} | {rss_mb:>6.1f}MB | {age_str:>6} | {status} | {p['cmd'][:60]}")
+            
+            if status in ("ZOMBIE", "STALE"):
+                zombies.append(p)
+            else:
+                keep.append(p)
+    
+    print()
+    print(f"Summary:")
+    print(f"  Total processes: {total}")
+    print(f"  Keep: {len(keep)}")
+    print(f"  Zombies: {len(zombies)}")
+    print(f"  Total RSS: {sum(p['rss_kb'] for p in processes) / 1024:.1f} MB")
+    
+    if args.status:
+        return 0
+    
+    if not zombies:
+        print()
+        print("No zombies to clean up.")
+        return 0
+    
+    if not args.kill:
+        print()
+        print("DRY RUN: Add --kill to terminate zombie processes")
+        return 0
+    
+    print()
+    print("Killing zombie processes...")
+    killed = 0
+    for p in zombies:
+        if kill_process(p["pid"], force=args.force):
+            killed += 1
+            print(f"  Killed PID {p['pid']}")
+        time.sleep(0.1)  # Brief pause between kills
+    
+    print(f"
+Killed {killed}/{len(zombies)} processes.")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())