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/app/cases/[caseNumber]/page.tsx

@@ -14,6 +14,7 @@ import { StatusGuide } from "@/components/cases/status-guide";
 import { StatusChanger } from "@/components/cases/status-changer";
 import { DocumentsPanel } from "@/components/cases/documents-panel";
 import { DraftsPanel } from "@/components/cases/drafts-panel";
+import { LegalArgumentsPanel } from "@/components/cases/legal-arguments-panel";
 import { AgentActivityFeed } from "@/components/cases/agent-activity-feed";
 import { AgentStatusWidget } from "@/components/cases/agent-status-widget";
 import { UploadSheet } from "@/components/documents/upload-sheet";
@@ -77,6 +78,9 @@ export default function CaseDetailPage({
                     <div className="flex items-center justify-between gap-3 mb-1 flex-wrap">
                       <TabsList className="bg-rule-soft/60">
                         <TabsTrigger value="overview">סקירה</TabsTrigger>
+                        <TabsTrigger value="arguments">
+                          טיעונים
+                        </TabsTrigger>
                         <TabsTrigger value="drafts">
                           טיוטות והערות
                         </TabsTrigger>
@@ -139,6 +143,10 @@ export default function CaseDetailPage({
                       <DocumentsPanel data={data} />
                     </TabsContent>
 
+                    <TabsContent value="arguments" className="mt-5">
+                      <LegalArgumentsPanel caseNumber={caseNumber} />
+                    </TabsContent>
+
                     <TabsContent value="drafts" className="mt-5">
                       <DraftsPanel
                         caseNumber={caseNumber}

web-ui/src/app/missing-precedents/page.tsx

@@ -0,0 +1,161 @@
+"use client";
+
+import { useState } from "react";
+import Link from "next/link";
+import { AppShell } from "@/components/app-shell";
+import { Card, CardContent } from "@/components/ui/card";
+import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
+import { Badge } from "@/components/ui/badge";
+import { Input } from "@/components/ui/input";
+import {
+  useMissingPrecedents,
+  type MissingPrecedentStatus,
+} from "@/lib/api/missing-precedents";
+import { MissingPrecedentsTable } from "@/components/missing-precedents/missing-precedents-table";
+
+/**
+ * Missing-precedents page (TaskMaster #35).
+ *
+ * Surfaces citations that party briefs invoke but which aren't yet in the
+ * precedent_library. Four tabs by status; each tab uses the same table
+ * component with a different filter. Drawer (sheet) opens on row click
+ * with metadata + upload form that routes to internal_decision_upload
+ * (ערר/בל"מ citations) or precedent_library_upload (court rulings).
+ */
+function StatusBadge({ status, count }: { status: MissingPrecedentStatus; count: number }) {
+  if (!count) return null;
+  const variants: Record<MissingPrecedentStatus, string> = {
+    open: "bg-gold-wash text-gold-deep border-gold/40",
+    uploaded: "bg-rule-soft text-ink-muted border-rule",
+    closed: "bg-emerald-50 text-emerald-800 border-emerald-300/60",
+    irrelevant: "bg-rule-soft text-ink-muted border-rule",
+  };
+  return (
+    <Badge
+      variant="outline"
+      className={`ms-1 text-[0.65rem] ${variants[status]}`}
+    >
+      {count}
+    </Badge>
+  );
+}
+
+export default function MissingPrecedentsPage() {
+  const [caseNumber, setCaseNumber] = useState("");
+  const [legalTopic, setLegalTopic] = useState("");
+
+  const counts = useMissingPrecedents({ limit: 1 });
+  const byStatus = counts.data?.by_status ?? {};
+
+  return (
+    <AppShell>
+      <section className="space-y-6">
+        <header>
+          <nav className="text-[0.78rem] text-ink-muted mb-1">
+            <Link href="/" className="hover:text-gold-deep">בית</Link>
+            <span aria-hidden> · </span>
+            <span className="text-navy">פסיקה חסרה בקורפוס</span>
+          </nav>
+          <h1 className="text-navy mb-0">פסיקה חסרה בקורפוס</h1>
+          <p className="text-ink-muted text-sm mt-1 max-w-3xl">
+            פסיקות שצוטטו בכתבי הטענות אך אינן עדיין בקורפוס. סוכן המחקר רושם
+            פערים אוטומטית; היו&quot;ר סוגר אותם על־ידי העלאת המסמך — ניתוב
+            אוטומטי בין הקורפוס הסמכותי (פסקי דין) להחלטות ועדות ערר.
+          </p>
+        </header>
+
+        <div className="h-[2px] bg-gradient-to-l from-transparent via-gold to-transparent" />
+
+        <Card className="bg-surface border-rule shadow-sm">
+          <CardContent className="px-6 py-5 space-y-5">
+            {/* Shared filters */}
+            <div className="flex items-end gap-3 flex-wrap">
+              <div className="flex-1 min-w-[200px]">
+                <label className="text-[0.78rem] text-ink-muted">תיק (מספר ערר)</label>
+                <Input
+                  value={caseNumber}
+                  onChange={(e) => setCaseNumber(e.target.value)}
+                  placeholder="1017-03-26"
+                  dir="rtl"
+                />
+              </div>
+              <div className="flex-1 min-w-[200px]">
+                <label className="text-[0.78rem] text-ink-muted">נושא משפטי</label>
+                <Input
+                  value={legalTopic}
+                  onChange={(e) => setLegalTopic(e.target.value)}
+                  placeholder="זכות עמידה"
+                  dir="rtl"
+                />
+              </div>
+            </div>
+
+            <Tabs defaultValue="open" dir="rtl">
+              <TabsList className="bg-rule-soft/60">
+                <TabsTrigger value="open">
+                  פתוחות
+                  <StatusBadge status="open" count={byStatus.open ?? 0} />
+                </TabsTrigger>
+                <TabsTrigger value="uploaded">
+                  הועלו
+                  <StatusBadge status="uploaded" count={byStatus.uploaded ?? 0} />
+                </TabsTrigger>
+                <TabsTrigger value="closed">
+                  נסגרו
+                  <StatusBadge status="closed" count={byStatus.closed ?? 0} />
+                </TabsTrigger>
+                <TabsTrigger value="irrelevant">
+                  לא רלוונטי
+                  <StatusBadge
+                    status="irrelevant"
+                    count={byStatus.irrelevant ?? 0}
+                  />
+                </TabsTrigger>
+                <TabsTrigger value="all">הכל</TabsTrigger>
+              </TabsList>
+
+              <TabsContent value="open" className="mt-4">
+                <MissingPrecedentsTable
+                  status="open"
+                  caseNumber={caseNumber.trim() || undefined}
+                  legalTopic={legalTopic.trim() || undefined}
+                />
+              </TabsContent>
+
+              <TabsContent value="uploaded" className="mt-4">
+                <MissingPrecedentsTable
+                  status="uploaded"
+                  caseNumber={caseNumber.trim() || undefined}
+                  legalTopic={legalTopic.trim() || undefined}
+                />
+              </TabsContent>
+
+              <TabsContent value="closed" className="mt-4">
+                <MissingPrecedentsTable
+                  status="closed"
+                  caseNumber={caseNumber.trim() || undefined}
+                  legalTopic={legalTopic.trim() || undefined}
+                />
+              </TabsContent>
+
+              <TabsContent value="irrelevant" className="mt-4">
+                <MissingPrecedentsTable
+                  status="irrelevant"
+                  caseNumber={caseNumber.trim() || undefined}
+                  legalTopic={legalTopic.trim() || undefined}
+                />
+              </TabsContent>
+
+              <TabsContent value="all" className="mt-4">
+                <MissingPrecedentsTable
+                  caseNumber={caseNumber.trim() || undefined}
+                  legalTopic={legalTopic.trim() || undefined}
+                />
+              </TabsContent>
+            </Tabs>
+          </CardContent>
+        </Card>
+      </section>
+    </AppShell>
+  );
+}