fix(telephony): handle Cloudonix CDR payloads missing session/disposition

The /cloudonix/cdr webhook is a public, unauthenticated endpoint that parses
arbitrary external JSON. It dereferenced cdr_data.get("session").get("token")
unconditionally, so a partial or malformed CDR payload that omits "session"
(or sends "session": null) raised AttributeError -> HTTP 500. The existing
"Missing call_id field" guard right below it was unreachable because the crash
happened first.

StatusCallbackRequest.from_cloudonix_cdr had the same fragility plus a second
one: data.get("disposition", "") returns None when the key is present-but-null,
and None.upper() then crashed.

Navigate both fields defensively so missing/null values fall through to the
intended graceful error path instead of crashing. Adds regression tests
covering missing session, null session, null disposition, and the well-formed
mapping path.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

api/services/telephony/providers/cloudonix/routes.py

@@ -103,7 +103,7 @@ async def handle_cloudonix_cdr(request: Request):
         return {"status": "error", "message": "Missing domain field"}
 
     # Extract call_id to find workflow run
-    call_id = cdr_data.get("session").get("token")
+    call_id = (cdr_data.get("session") or {}).get("token")
     logger.info(f"Cloudonix CDR data for call id {call_id} - {cdr_data}")
     if not call_id:
         logger.warning("Cloudonix CDR missing call_id field")

api/services/telephony/status_processor.py

@@ -114,11 +114,11 @@ class StatusCallbackRequest(BaseModel):
             "NOANSWER": "no-answer",
         }
 
-        disposition = data.get("disposition", "")
+        disposition = data.get("disposition") or ""
         status = disposition_map.get(disposition.upper(), disposition.lower())
 
         return cls(
-            call_id=data.get("session").get("token"),
+            call_id=(data.get("session") or {}).get("token") or "",
             status=status,
             from_number=data.get("from"),
             to_number=data.get("to"),