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>

mcp-server/tests/test_corpus_constraints.py

@@ -0,0 +1,276 @@
+"""Regression tests for Stage-A corpus integrity fixes (TaskMaster #30, #31).
+
+These tests document the bugs that were closed in Stage A so they don't
+regress quietly. Each test maps to a real bug or constraint:
+
+  1. DB CHECK ``cases_practice_area_check`` rejects the legacy
+     ``'appeals_committee'`` value — only domain values (rishuy_uvniya /
+     betterment_levy / compensation_197) and ``''`` are allowed.
+     (Bug: many ``cases`` rows stored ``'appeals_committee'`` instead of
+     the domain.)
+
+  2. DB CHECK ``case_law_internal_chair_check`` and
+     ``case_law_internal_district_check`` reject internal_committee rows
+     with empty chair_name/district.
+     (Bug: 6 records had source_kind='external_upload' but were really
+     internal committee decisions; the flip to internal_committee in
+     Stage A.2 surfaced the missing chair/district fields.)
+
+  3. DB CHECK ``case_law_external_arar_check`` rejects external_upload
+     rows whose case_number starts with ``"ערר"`` or ``"בל\\"מ"`` —
+     committee decisions must go through internal_decision_upload, not
+     precedent_library_upload.
+     (Bug: the legacy upload path stored everything as external_upload,
+     including appeal-committee decisions; the citation guard now
+     redirects them.)
+
+  4. MCP tool ``precedent_library_upload`` returns an ``_err`` envelope
+     when the citation starts with ``"ערר"`` (citation guard, not DB
+     constraint — fires before INSERT to surface a helpful error).
+
+These tests connect to the live local Postgres (port 5433) — they do not
+mock asyncpg. Run with::
+
+    pytest mcp-server/tests/test_corpus_constraints.py -v
+
+If you don't have ``DATABASE_URL`` set, the tests are skipped.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import json
+import os
+from uuid import uuid4
+
+import asyncpg
+import pytest
+
+
+def _dsn() -> str | None:
+    return (
+        os.environ.get("DATABASE_URL")
+        or os.environ.get("LEGAL_AI_DATABASE_URL")
+        or "postgresql://legal_ai:od0ASJZFYibOlWK59krLvvETmgqwlXe8@localhost:5433/legal_ai"
+    )
+
+
+@pytest.fixture()
+def dsn() -> str:
+    d = _dsn()
+    if not d:
+        pytest.skip("No DATABASE_URL set; skipping live-DB regression tests")
+    return d
+
+
+@pytest.fixture()
+def event_loop():
+    """Provide a fresh event loop per test so asyncpg doesn't leak across cases."""
+    loop = asyncio.new_event_loop()
+    try:
+        yield loop
+    finally:
+        loop.close()
+
+
+def _run(loop, coro):
+    return loop.run_until_complete(coro)
+
+
+# ── 1. cases.practice_area CHECK ─────────────────────────────────────
+
+
+def test_cases_rejects_appeals_committee_practice_area(dsn: str, event_loop) -> None:
+    """``cases.practice_area = 'appeals_committee'`` must violate the CHECK."""
+
+    async def attempt() -> None:
+        conn = await asyncpg.connect(dsn)
+        try:
+            with pytest.raises(asyncpg.exceptions.CheckViolationError):
+                await conn.execute(
+                    """INSERT INTO cases (id, case_number, title, practice_area)
+                       VALUES ($1, $2, $3, $4)""",
+                    uuid4(), f"TEST-{uuid4().hex[:8]}", "regression-test",
+                    "appeals_committee",
+                )
+        finally:
+            await conn.close()
+
+    _run(event_loop, attempt())
+
+
+def test_cases_accepts_domain_practice_area(dsn: str, event_loop) -> None:
+    """Sanity check: rishuy_uvniya / betterment_levy / compensation_197
+    + empty string must be accepted."""
+
+    async def attempt() -> None:
+        conn = await asyncpg.connect(dsn)
+        try:
+            tx = conn.transaction()
+            await tx.start()
+            try:
+                for value in ("rishuy_uvniya", "betterment_levy",
+                              "compensation_197", ""):
+                    await conn.execute(
+                        """INSERT INTO cases (id, case_number, title, practice_area)
+                           VALUES ($1, $2, $3, $4)""",
+                        uuid4(), f"TEST-{uuid4().hex[:8]}",
+                        f"regression-{value or 'empty'}", value,
+                    )
+            finally:
+                await tx.rollback()
+        finally:
+            await conn.close()
+
+    _run(event_loop, attempt())
+
+
+# ── 2. case_law internal_committee chair/district CHECK ─────────────
+
+
+def test_case_law_internal_requires_chair_and_district(dsn: str, event_loop) -> None:
+    """``case_law`` rows with ``source_kind='internal_committee'`` must have
+    non-empty ``chair_name`` AND ``district``."""
+
+    async def attempt_missing_chair() -> None:
+        conn = await asyncpg.connect(dsn)
+        try:
+            with pytest.raises(asyncpg.exceptions.CheckViolationError):
+                await conn.execute(
+                    """INSERT INTO case_law (id, case_number, case_name,
+                           source_kind, district, chair_name)
+                       VALUES ($1, $2, $3, $4, $5, $6)""",
+                    uuid4(), f"ערר {uuid4().hex[:6]}",
+                    "test internal w/o chair",
+                    "internal_committee", "ירושלים", "",
+                )
+        finally:
+            await conn.close()
+
+    async def attempt_missing_district() -> None:
+        conn = await asyncpg.connect(dsn)
+        try:
+            with pytest.raises(asyncpg.exceptions.CheckViolationError):
+                await conn.execute(
+                    """INSERT INTO case_law (id, case_number, case_name,
+                           source_kind, district, chair_name)
+                       VALUES ($1, $2, $3, $4, $5, $6)""",
+                    uuid4(), f"ערר {uuid4().hex[:6]}",
+                    "test internal w/o district",
+                    "internal_committee", "", "עו\"ד דפנה תמיר",
+                )
+        finally:
+            await conn.close()
+
+    _run(event_loop, attempt_missing_chair())
+    _run(event_loop, attempt_missing_district())
+
+
+# ── 3. case_law external_upload + ערר citation CHECK ────────────────
+
+
+def test_case_law_external_upload_rejects_arar_citation(dsn: str, event_loop) -> None:
+    """``case_law`` rows with ``source_kind='external_upload'`` cannot have
+    a ``case_number`` that starts with ``"ערר"`` or ``"בל\"מ"`` — those
+    are committee decisions and must use ``source_kind='internal_committee'``."""
+
+    async def attempt_arar() -> None:
+        conn = await asyncpg.connect(dsn)
+        try:
+            with pytest.raises(asyncpg.exceptions.CheckViolationError):
+                await conn.execute(
+                    """INSERT INTO case_law (id, case_number, case_name,
+                           source_kind)
+                       VALUES ($1, $2, $3, $4)""",
+                    uuid4(), "ערר 1170/24 חיים נ' ועדה",
+                    "test external arar", "external_upload",
+                )
+        finally:
+            await conn.close()
+
+    async def attempt_balam() -> None:
+        conn = await asyncpg.connect(dsn)
+        try:
+            with pytest.raises(asyncpg.exceptions.CheckViolationError):
+                await conn.execute(
+                    """INSERT INTO case_law (id, case_number, case_name,
+                           source_kind)
+                       VALUES ($1, $2, $3, $4)""",
+                    uuid4(), 'בל"מ 1234/25 פלוני',
+                    "test external balam", "external_upload",
+                )
+        finally:
+            await conn.close()
+
+    _run(event_loop, attempt_arar())
+    _run(event_loop, attempt_balam())
+
+
+# ── 4. MCP precedent_library_upload citation guard ──────────────────
+
+
+def test_mcp_precedent_upload_rejects_arar_citation() -> None:
+    """The MCP tool ``precedent_library_upload`` must short-circuit
+    citations that start with ``"ערר"`` / ``"בל\"מ"`` and return an
+    ``_err`` envelope (a helpful message redirecting to
+    ``internal_decision_upload``), without touching the DB."""
+
+    from legal_mcp.tools import precedent_library as tools
+
+    async def call(citation: str) -> dict:
+        # file_path won't be touched because the guard fires first.
+        return json.loads(
+            await tools.precedent_library_upload(
+                file_path="/nonexistent",
+                citation=citation,
+            )
+        )
+
+    loop = asyncio.new_event_loop()
+    try:
+        for citation in (
+            "ערר 1170/24 חיים נ' ועדה",
+            'בל"מ 1234/25 פלוני',
+            "ARAR 8126-25 ב. קרן-נכסים",
+        ):
+            result = loop.run_until_complete(call(citation))
+            assert "error" in result, (
+                f"expected guard to reject {citation!r}, got {result!r}"
+            )
+            # The error message should mention internal_decision_upload so
+            # the caller knows the alternative path.
+            assert "internal_decision_upload" in result["error"], (
+                f"error message should redirect to internal_decision_upload, "
+                f"got {result['error']!r}"
+            )
+    finally:
+        loop.close()
+
+
+def test_practice_area_module_invariants() -> None:
+    """Quick guard that the ``practice_area`` service module exposes the
+    helpers tools and tests depend on, and that derivation is consistent
+    with the case-number convention (1xxx/8xxx/9xxx)."""
+
+    from legal_mcp.services import practice_area as pa
+
+    # Domain mapping is consistent with the case-number prefix convention.
+    assert pa.derive_domain_practice_area("1170") == "rishuy_uvniya"
+    assert pa.derive_domain_practice_area("8126/25") == "betterment_levy"
+    assert pa.derive_domain_practice_area("9001") == "compensation_197"
+    assert pa.derive_domain_practice_area("ARAR-25-8126") == "betterment_levy"
+    # Unparseable input → empty (caller decides fallback).
+    assert pa.derive_domain_practice_area("foo") == ""
+    assert pa.derive_domain_practice_area("") == ""
+
+    # Empty practice_area is valid (DB allows it as 'unclassified').
+    pa.validate("", "unknown")
+    pa.validate("rishuy_uvniya", "building_permit")
+    pa.validate("betterment_levy", "betterment_levy")
+
+    # appeals_committee (axis A) is still recognised for backward-compat.
+    pa.validate("appeals_committee", "building_permit")
+
+    # is_override returns False when subtype matches derivation.
+    assert pa.is_override("1170", "rishuy_uvniya", "building_permit") is False
+    assert pa.is_override("8126", "betterment_levy", "betterment_levy") is False