perf(registratura): lightweight API mode strips base64 attachments from list

ROOT CAUSE: RegistryEntry stores file attachments as base64 strings in JSON.
A single 5MB PDF becomes ~6.7MB of base64. With 6 entries, the exportAll()
endpoint was sending 30-60MB of JSON on every page load  taking 2+ minutes.

Fix: Added ?lightweight=true parameter to /api/storage GET endpoint.
When enabled, stripHeavyFields() recursively removes large 'data' and
'fileData' string fields (>1KB) from JSON values, replacing with '__stripped__'.

Changes:
- /api/storage route.ts: stripHeavyFields() + lightweight query param
- StorageService.export(): accepts { lightweight?: boolean } option
- DatabaseStorageAdapter.export(): passes lightweight flag to API
- LocalStorageAdapter.export(): accepts option (no-op, localStorage is fast)
- useStorage.exportAll(): passes options through
- registry-service.ts: getAllEntries() uses lightweight=true by default
- registry-service.ts: new getFullEntry() loads single entry with full data
- use-registry.ts: exports loadFullEntry() for on-demand full loading
- registratura-module.tsx: handleEdit/handleNavigateEntry load full entry

Result: List loading transfers ~100KB instead of 30-60MB. Editing loads
full data for a single entry on demand (~5-10MB for one entry vs all).

src/modules/registratura/components/registratura-module.tsx

@@ -49,6 +49,7 @@ export function RegistraturaModule() {
     updateEntry,
     removeEntry,
     closeEntry,
+    loadFullEntry,
     addDeadline,
     resolveDeadline,
     removeDeadline,
@@ -120,13 +121,16 @@ export function RegistraturaModule() {
     setViewMode("list");
   };
 
-  const handleEdit = (entry: RegistryEntry) => {
-    setEditingEntry(entry);
+  const handleEdit = async (entry: RegistryEntry) => {
+    // Load full entry with attachment data (list mode strips base64)
+    const full = await loadFullEntry(entry.id);
+    setEditingEntry(full ?? entry);
     setViewMode("edit");
   };
 
-  const handleNavigateEntry = (entry: RegistryEntry) => {
-    setEditingEntry(entry);
+  const handleNavigateEntry = async (entry: RegistryEntry) => {
+    const full = await loadFullEntry(entry.id);
+    setEditingEntry(full ?? entry);
     setViewMode("edit");
   };