fix: address code review findings

- Add retry (2 attempts) on CivitAI 429 rate limit instead of silently skipping
- Use check_same_thread=False for SQLite connection (aiohttp context)
- Add debug logging to silent exception handlers in proxy

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

proxy.py

@@ -599,8 +599,8 @@ async def lm_remote_proxy_middleware(request: web.Request, handler):
                 body = json.loads(response.body)
                 enriched = _enrich_list_response(body)
                 return web.json_response(enriched)
-            except Exception:
-                pass  # Return original response on any error
+            except Exception as exc:
+                logger.debug("[LM-Remote] Stats enrichment failed: %s", exc)
         # Inject stats UI script into HTML pages
         if (path in _PROXY_PAGE_ROUTES or path.rstrip("/") in _PROXY_PAGE_ROUTES):
             if response.status == 200:
@@ -616,8 +616,8 @@ async def lm_remote_proxy_middleware(request: web.Request, handler):
                             charset="utf-8",
                             status=response.status,
                         )
-                    except Exception:
-                        pass
+                    except Exception as exc:
+                        logger.debug("[LM-Remote] HTML injection failed: %s", exc)
         return response
 
     # Not a LoRA Manager route — fall through