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

auth.py

@@ -1,5 +1,5 @@
 """
-JarvisChat - Auth: session management, PIN verification, middleware, auth routes.
+cAIc - Auth: session management, PIN verification, middleware, auth routes.
 """
 import hashlib
 import hmac
@@ -21,7 +21,7 @@ from security import (
     read_json_body, hash_pin, customer_error_envelope, log_incident,
 )
 
-log = logging.getLogger("jarvischat")
+log = logging.getLogger("caic")
 router = APIRouter()