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/routes/handlers/agent_handlers.py

@@ -99,12 +99,11 @@ class AgentHandler:
         # Launch execution in the background
         progress_reporter = AgentProgressReporter()
         logger.info(
-            "LLM enrichment '%s' starting for %d model(s) in background task",
+            "LLM enrichment '%s' starting for %d model(s)",
             skill_name, len(model_paths),
         )
 
         async def _run() -> None:
-            logger.info("Background task started for enrichment '%s'", skill_name)
             try:
                 result = await service.execute_skill(
                     skill_name=skill_name,
@@ -137,8 +136,7 @@ class AgentHandler:
                 )
 
         # Fire and forget — progress comes via WebSocket
-        task = asyncio.create_task(_run())
-        logger.info("LLM enrichment '%s' background task created (id=%s)", skill_name, task)
+        asyncio.create_task(_run())
 
         return web.json_response(
             {