fix(panels): resolve sidebar refresh bugs — getUser→getSession, files double-call, hardcoded IP

- transcriptionStore: replace all supabase.auth.getUser() with getSession() so session
  restoration on page refresh does not race against GoTrue network validation
- CCFilesPanel: remove selectedCabinet from loadCabinets useCallback deps; use
  initialSelectionDone ref to prevent double-call on first mount
- CCTranscriptionPanel: replace hardcoded LAN IP with VITE_API_URL env var

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

src/utils/tldraw/ui-overrides/components/shared/CCFilesPanel.tsx

@@ -115,6 +115,7 @@ export const CCFilesPanel: React.FC = () => {
   const [breadcrumbs, setBreadcrumbs] = useState<{ id: string | null; name: string }[]>([
     { id: null, name: 'Root' }
   ]);
+  const initialSelectionDone = useRef(false);
 
   // Directory upload state
   const [selectedFiles, setSelectedFiles] = useState<FileWithPath[]>([]);
@@ -158,13 +159,16 @@ export const CCFilesPanel: React.FC = () => {
       const data = await apiFetch('/database/cabinets');
       const all = [...(data.owned || []), ...(data.shared || [])];
       setCabinets(all);
-      if (all.length && !selectedCabinet) setSelectedCabinet(all[0].id);
+      if (all.length && !initialSelectionDone.current) {
+        initialSelectionDone.current = true;
+        setSelectedCabinet(all[0].id);
+      }
     } catch (error) {
       console.error('Failed to load cabinets:', error);
     } finally {
       setLoading(false);
     }
-  }, [selectedCabinet, apiFetch]);
+  }, [apiFetch]);
 
   const loadFiles = useCallback(async (cabinetId: string, page: number = currentPage) => {
     if (!cabinetId) return;