Rename: jarvisChat → cAIc (product name)

- jarvisChat/JarvisChat/jarvischat → cAIc/cAIc/caic (branded/lower)
- JARVISCHAT_ env vars → CAIC_
- jc- script/config prefix → caic-
- jarvis_rag → caic_rag
- jarvischat.db / volumes → caic.db / caic_*
- AMQP vhost/user jarvischat → caic
- Syslog, loggers, docstrings all updated
- 47 files, zero stale references, 148 tests pass

amqp.py

@@ -1,5 +1,5 @@
 """
-JarvisChat — AMQP connection manager.
+cAIc — AMQP connection manager.
 Single persistent aio-pika connection with auto-reconnect.
 """
 import asyncio
@@ -21,7 +21,7 @@ from config import (
     get_amqp_url,
 )
 
-log = logging.getLogger("jarvischat")
+log = logging.getLogger("caic")
 
 _connection = None
 _channel = None