fix(precedents): allow delete when extraction completed but timestamp stale

The local MCP worker is supposed to NULL `*_extraction_requested_at` after
a successful run, but in practice these timestamps linger. The previous
isPrecedentActive logic treated any non-null timestamp as "still active",
which left completed rows permanently undeletable.

Now only "processing" status (or genuinely queued: pending + timestamp)
counts as active. Once a row is "completed"/"failed", stale timestamps
no longer block the delete button.

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

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

@@ -187,13 +187,37 @@ export function usePrecedents(filters: ListFilters = {}) {
 }
 
 /** A precedent is "active" while text/halacha extraction is in flight or
- * queued for the local MCP worker. Used by the auto-refresh poller and
- * by the row UI to disable destructive actions. */
+ * legitimately queued for the local MCP worker. Used by the auto-refresh
+ * poller and by the row UI to disable destructive actions.
+ *
+ * Once a status is "completed" or "failed", the row is NEVER active —
+ * even if the corresponding `*_requested_at` timestamp still has a value.
+ * The worker is supposed to NULL it on success but in practice doesn't
+ * always, and treating those rows as active leaves them permanently
+ * undeletable. */
 export function isPrecedentActive(p: Precedent): boolean {
+  // Text extraction
   if (p.extraction_status === "processing") return true;
+
+  // Halacha extraction
   if (p.halacha_extraction_status === "processing") return true;
-  if (p.halacha_extraction_requested_at !== null) return true;
-  if (p.metadata_extraction_requested_at !== null) return true;
+  if (
+    p.halacha_extraction_status === "pending" &&
+    p.halacha_extraction_requested_at !== null
+  ) {
+    return true;
+  }
+
+  // Metadata extraction has no status column — only the timestamp.
+  // Treat as active only when extraction hasn't yet fully completed
+  // (otherwise stale timestamps linger after success).
+  if (
+    p.metadata_extraction_requested_at !== null &&
+    p.extraction_status !== "completed"
+  ) {
+    return true;
+  }
+
   return false;
 }