fix: Proper deque serialization for JSON API

- Add deque_to_list helper for safe serialization
- Use getattr to safely access nested attributes
- Fix coherence endpoint to return properly serializable data

simple_witness.py

@@ -0,0 +1,90 @@
+#!/usr/bin/env python3
+"""
+simple_witness.py
+
+Simple witness check for BECOMINGONE instances.
+
+Polls a target instance and commits observations.
+Run this on witness-seed to watch the Mac mini.
+
+Usage:
+    python3 simple_witness.py --target http://localhost:8000 --name "mac-mini"
+    python3 simple_witness.py --target http://198.12.71.159:8000 --name "witness-seed"
+"""
+
+import argparse
+import json
+import subprocess
+import sys
+import time
+from datetime import datetime
+from pathlib import Path
+
+import httpx
+
+
+def witness(target_url: str, name: str) -> dict:
+    """Witness a BECOMINGONE instance."""
+    observation = {
+        "timestamp": datetime.utcnow().isoformat(),
+        "witness": name,
+        "target": target_url,
+        "target_up": False,
+        "health": None,
+        "coherence": None,
+    }
+    
+    try:
+        # Health check
+        resp = httpx.get(f"{target_url}/health", timeout=5)
+        if resp.status_code == 200:
+            observation["health"] = resp.json()
+            observation["target_up"] = True
+        
+        # Coherence check
+        resp = httpx.get(f"{target_url}/coherence", timeout=5)
+        if resp.status_code == 200:
+            observation["coherence"] = resp.json()
+    
+    except Exception as e:
+        observation["error"] = str(e)
+    
+    return observation
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Simple BECOMINGONE witness")
+    parser.add_argument("--target", required=True, help="Target URL")
+    parser.add_argument("--name", required=True, help="Witness name")
+    parser.add_argument("--output", help="Output file")
+    args = parser.parse_args()
+    
+    obs = witness(args.target, args.name)
+    
+    # Print result
+    status = "✅" if obs["target_up"] else "❌"
+    print(f"{status} {obs['witness']} -> {obs['target']}")
+    
+    if obs["target_up"]:
+        c = obs.get("coherence", {})
+        print(f"   Master: {c.get('master_coherence', 'N/A')}")
+        print(f"   Emissary: {c.get('emissary_coherence', 'N/A')}")
+        print(f"   Sync aligned: {c.get('sync_aligned', 'N/A')}")
+    else:
+        print(f"   Error: {obs.get('error', 'Unknown')}")
+    
+    # Save to file
+    output_file = args.output or f"witness_{name_to_file(args.name)}.json"
+    with open(output_file, "w") as f:
+        json.dump(obs, f, indent=2, default=str)
+    
+    print(f"\nSaved to {output_file}")
+
+
+def name_to_file(name: str) -> str:
+    """Convert name to filename-safe string."""
+    return name.replace(" ", "-").replace("/", "-")
+
+
+if __name__ == "__main__":
+    main()