fix(llm): add fetch-models endpoint, fix SQL Lab INSERT (client_id truncation, sync mode, target_column, timestamp normalization)

- Add POST /api/llm/providers/fetch-models route with LLMClient.fetch_models()
- Add target_column to TranslationJob model/schema/service/orchestrator
- Fix SQL Lab execute: truncate client_id to 11 chars (varchar(11))
- Switch SQL Lab to sync mode (runAsync: false) — no Celery workers
- Fix polling: unwrap nested result from Superset query API
- Fix ClickHouse timestamp: normalize float timestamps to YYYY-MM-DD

backend/src/services/git/_status.py

@@ -13,7 +13,6 @@ from src.core.logger import logger, belief_scope
 # @BRIEF Mixin providing repository status, diff, and commit history for GitService.
 class GitServiceStatusMixin:
     # region _parse_status_porcelain [TYPE Function]
-    # @COMPLEXITY: 2
     # @PURPOSE: Parse git status --porcelain output into staged, modified, and untracked file lists.
     # @PRE: `repo` is an open GitPython Repo instance.
     # @POST: Returns (staged, modified, untracked) tuple of file path lists.