Make port configurable (default 5100)

- Port now set via config.json "port" field
- Aggregator reads PORT from environment variable
- Updated all docs and scripts to use port 5100

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

aggregator.py

@@ -4,6 +4,7 @@ A lightweight event broker that manages priority-based system status.
 """
 
 import json
+import os
 import random
 import threading
 import time
@@ -252,6 +253,8 @@ def list_events():
 
 
 def main():
+    port = int(os.environ.get("PORT", 5100))
+
     # Write initial optimal state
     write_status()
     print(f"Status file: {STATUS_FILE}")
@@ -261,7 +264,7 @@ def main():
     cleanup_thread.start()
 
     # Run Flask
-    app.run(host="0.0.0.0", port=5000, threaded=True)
+    app.run(host="0.0.0.0", port=port, threaded=True)
 
 
 if __name__ == "__main__":