feat(precedents): metadata auto-fill, edit sheet, persuasive extraction

Three improvements to the precedent library based on usage feedback:

1. Auto-fill metadata at upload time. New service
   precedent_metadata_extractor reads the ruling's full_text and
   suggests case_name (short), summary, headnote, key_quote,
   subject_tags, appeal_subtype. The merge policy fills only empty
   fields, preserving everything the chair typed in the upload form.
   Wired into the ingest pipeline; also exposed as a re-run endpoint
   POST /api/precedent-library/{id}/extract-metadata for existing
   records.

2. Edit sheet in the UI. Pencil icon on each library row opens a
   pre-populated form covering every field. A Sparkles button on the
   sheet runs the metadata extractor on demand and refreshes the
   form. The case_number is read-only because halachot are FK'd to
   it; renaming requires delete + re-upload.

3. Halacha extractor branches on is_binding. Sources marked binding
   (Supreme/Administrative) keep the strict halacha prompt. Non-binding
   sources (other appeals committees, district courts on planning
   matters) get a different prompt that extracts applications,
   interpretive principles, and persuasive conclusions — labeled with
   new rule_types 'application' and 'persuasive'. The fallback also
   widens chunk selection: if the chunker labeled nothing as
   legal_analysis/ruling/conclusion, we now run on all chunks rather
   than returning zero halachot for a usable ruling.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web-ui/src/lib/api/precedent-library.ts

@@ -350,6 +350,21 @@ export function useReExtractHalachot() {
   });
 }
 
+export function useReExtractMetadata() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: (id: string) =>
+      apiRequest<{ task_id: string }>(
+        `/api/precedent-library/${encodeURIComponent(id)}/extract-metadata`,
+        { method: "POST" },
+      ),
+    onSuccess: (_, id) => {
+      qc.invalidateQueries({ queryKey: libraryKeys.detail(id) });
+      qc.invalidateQueries({ queryKey: libraryKeys.all });
+    },
+  });
+}
+
 export function useHalachotPending(limit = 200) {
   return useQuery({
     queryKey: libraryKeys.halachotPending(),