refactor(agent): rename agent_cli to metadata_ops, strip temp debug logs

- Rename py/agent_cli/ -> py/metadata_ops/ (module was never agent-related)
- Rename tests/agent_cli/ -> tests/metadata_ops/
- Remove 9 low-value/debug INFO log points across agent_handlers.py,
  agent_service.py, llm_service.py, and metadata_ops/__init__.py
- Keep LLM raw response at DEBUG level for diagnostics
- Consolidate per-model progress + LLM result into single concise
  log line with basename instead of full path
- Update package/class/method docstrings to clarify this is a
  pipeline infrastructure, not a true agent loop

py/services/llm_service.py

@@ -521,15 +521,9 @@ class LLMService:
 
         try:
             parsed = json.loads(result["content"])
-            logger.info(
-                "LLM response base_model=%s tags=%s confidence=%s",
-                parsed.get("base_model", "?")[:50],
-                parsed.get("tags", []),
-                parsed.get("confidence", "?"),
-            )
-            logger.info(
+            logger.debug(
                 "LLM raw content: %s",
-                (result.get("content") or "")[:1200],
+                json.dumps(parsed, ensure_ascii=False)[:2000],
             )
             return parsed
         except (json.JSONDecodeError, TypeError) as exc: