feat: Stage A finalizers + #35/#36/#37 — critical-gap closure

Four parallel sub-agents closed the remaining critical gaps from the
26/05 Stage A/B sprint. Each block independently tested; aggregated here.

## #30/#31 finalizers (sub-agent A)
* Auto-derive practice_area in case_create from case_number prefix
  (1xxx→rishuy_uvniya, 8xxx→betterment_levy, 9xxx→compensation_197);
  default for CaseCreateRequest is now "" (the DB constraint catches
  any stray "appeals_committee").
* practice_area.py: derive_subtype now handles axis-B domain values
  (rishuy_uvniya/betterment_levy/compensation_197) without parsing the
  case number; new helper derive_domain_practice_area().
* Halacha re-extraction verified unnecessary — all 6 reclassified
  records already had is_binding=false and approved halachot.
* Regression tests: 6 cases in tests/test_corpus_constraints.py
  covering practice_area enum, internal-committee chair/district,
  external-upload arar prefix, MCP guard.
* UI: district input → Select dropdown (7 districts) in
  precedent-edit-sheet.tsx, preserving legacy free-text values.

## #37 בל"מ subtypes (sub-agent B)
* 3 new appeal_subtypes: extension_request_{building_permit,
  betterment_levy,compensation}. APPEALS_COMMITTEE_SUBTYPES extended,
  SUBTYPES_BY_AREA mappings added.
* New helpers: is_blam_subject(), is_blam_subtype(),
  derive_subtype_with_blam(case_number, subject, practice_area).
  case_create now uses it to auto-detect "בקשה להארכת מועד" subjects.
* 3 methodology templates under docs/methodology/extension-request-*.md.
* paperclip_client.py mapping updated for the 3 new subtypes
  (extension_request_building_permit→CMP, the other two→CMPA).
* Frontend: bilingual "בל"מ" badge + filter dropdown on cases list +
  detail header; appeal-type-bars collapseBlam() merges בל"מ into its
  parent domain for aggregate bars.
* Wizard auto-detects בל"מ from subject during case creation.
* 3 Berlinger cases (1017/1018/1019-03-26) migrated to
  appeal_subtype=extension_request_building_permit via psql.

## #35 missing_precedents feature (sub-agent C)
* Schema V13: missing_precedents table (citation, case_id, party,
  legal_topic, status, linked_case_law_id, claim_quote, ...) +
  FK constraints + 3 indexes. Applied via psql + idempotent migration.
* 6 db.py service functions, 3 MCP tools, 6 FastAPI endpoints
  (POST/GET/PATCH/DELETE/upload — upload routes by citation prefix
  to ingest_internal_decision or ingest_precedent).
* Next.js page /missing-precedents with 5 status tabs + filters +
  sidebar badge counter + detail drawer with metadata edit + smart
  upload form that switches fields per committee/court.
* Bootstrap: 7 rows imported from the JSON file
  (3 citations × cases, all status=closed with linked_case_law_id).
* legal-researcher.md: new §2ב.5 with missing_precedent_create
  usage + dedup semantics + tool grant.

## #36 legal_arguments aggregation (sub-agent D)
* Schema V14: legal_arguments + legal_argument_propositions M:M.
  Applied via psql.
* New service argument_aggregator.py with two functions —
  aggregate_claims_to_arguments() (Claude CLI / claude_session) and
  get_legal_arguments(). Graceful llm_unavailable handling when CLI
  is missing (containers).
* 2 MCP tools + 2 API endpoints (POST .../aggregate-arguments as
  BackgroundTask, GET .../legal-arguments).
* Frontend: shadcn Accordion + new legal-arguments-panel.tsx with
  hierarchical (party → priority badge → arguments) display, "טיעונים"
  tab on the case page, "חשב/חשב מחדש" buttons.
* scripts/backfill_legal_arguments.py + SCRIPTS.md entry — dry-run
  found 8 candidate cases including 1017/1018/1019.

## Open follow-ups (intentionally deferred)
* npm run api:types in web-ui (CLAUDE.md flow) — recommended before
  the next UI commit; not required for backend deployment.
* Run backfill_legal_arguments.py --apply once the container picks up
  the new aggregator service.
* webhook on missing-precedents upload-close to Paperclip (optional).

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

web-ui/src/components/cases/cases-table.tsx

@@ -16,7 +16,12 @@ import {
 } from "@/components/ui/table";
 import { Input } from "@/components/ui/input";
 import { Skeleton } from "@/components/ui/skeleton";
+import { Badge } from "@/components/ui/badge";
+import {
+  Select, SelectContent, SelectItem, SelectTrigger, SelectValue,
+} from "@/components/ui/select";
 import { StatusBadge } from "@/components/cases/status-badge";
+import { isBlamSubtype } from "@/lib/practice-area";
 import type { Case } from "@/lib/api/cases";
 
 function formatDate(iso?: string) {
@@ -49,8 +54,17 @@ const columns: ColumnDef<Case>[] = [
     accessorKey: "title",
     header: "כותרת",
     cell: ({ row }) => (
-      <div className="text-ink max-w-[420px] truncate" title={row.original.title}>
-        {row.original.title}
+      <div className="text-ink max-w-[420px] truncate flex items-center gap-2" title={row.original.title}>
+        {isBlamSubtype(row.original.appeal_subtype) && (
+          <Badge
+            variant="outline"
+            className="rounded-full px-1.5 py-0 text-[0.65rem] font-bold bg-warn/10 text-warn-deep border-warn/40 shrink-0"
+            title="בקשה להארכת מועד להגשת ערר"
+          >
+            בל&quot;מ
+          </Badge>
+        )}
+        <span className="truncate">{row.original.title}</span>
       </div>
     ),
   },
@@ -94,8 +108,15 @@ export function CasesTable({
     { id: "updated_at", desc: true },
   ]);
   const [globalFilter, setGlobalFilter] = useState("");
+  /* "all" = all cases; "blam" = only בל"מ; "regular" = exclude בל"מ */
+  const [blamFilter, setBlamFilter] = useState<"all" | "blam" | "regular">("all");
 
-  const data = useMemo(() => cases ?? [], [cases]);
+  const data = useMemo(() => {
+    const all = cases ?? [];
+    if (blamFilter === "blam") return all.filter((c) => isBlamSubtype(c.appeal_subtype));
+    if (blamFilter === "regular") return all.filter((c) => !isBlamSubtype(c.appeal_subtype));
+    return all;
+  }, [cases, blamFilter]);
 
   const table = useReactTable({
     data,
@@ -126,6 +147,20 @@ export function CasesTable({
           className="max-w-sm bg-surface"
           dir="rtl"
         />
+        <Select
+          value={blamFilter}
+          onValueChange={(v) => setBlamFilter(v as "all" | "blam" | "regular")}
+          dir="rtl"
+        >
+          <SelectTrigger className="w-40 bg-surface">
+            <SelectValue />
+          </SelectTrigger>
+          <SelectContent>
+            <SelectItem value="all">כל התיקים</SelectItem>
+            <SelectItem value="blam">בל&quot;מ בלבד</SelectItem>
+            <SelectItem value="regular">ערר רגיל בלבד</SelectItem>
+          </SelectContent>
+        </Select>
         <span className="text-sm text-ink-muted me-auto">
           {table.getFilteredRowModel().rows.length} תיקים
         </span>