v0.22.1: dockerize defaults, harden error handling, fix test discovery

- config.py: defaults to localhost/localhost, AMQP to rabbitmq, secret
  path to /run/secrets, RAG_MAX_VECTORS from env
- rag.py: EMBED_URL default to localhost
- app.py: syslog handler wrapped in try/except
- routers/completions.py: db.close() in try/finally
- db.py: PRAGMA journal_mode = WAL
- amqp.py: subscription append before try for reconnect safety
- tests/conftest.py: add project root to sys.path for test discovery

rag.py

@@ -16,7 +16,7 @@ from config import MAX_SKILL_PROMPT_CHARS, QDRANT_URL, RAG_COLLECTION
 
 log = logging.getLogger("caic")
 
-EMBED_URL = os.environ.get("CAIC_EMBED_URL", "http://192.168.50.210:11434")
+EMBED_URL = os.environ.get("CAIC_EMBED_URL", "http://localhost:11434")
 EMBED_MODEL = os.environ.get("CAIC_EMBED_MODEL", "mxbai-embed-large")
 RAG_SCORE_THRESHOLD = 0.25