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/src/legal_mcp/services/practice_area.py

@@ -52,16 +52,44 @@ DOMAIN_PRACTICE_AREAS: set[str] = {
     "compensation_197",
 }
 
-# Union — what ``validate()`` accepts for backward-compat
-PRACTICE_AREAS: set[str] = MULTI_TENANT_PRACTICE_AREAS | DOMAIN_PRACTICE_AREAS
+# Union — what ``validate()`` accepts for backward-compat.
+# Empty string is permitted because the DB CHECK constraint allows it as
+# a "not yet classified" sentinel (e.g. when auto-derivation fails on an
+# unrecognized case_number format).
+PRACTICE_AREAS: set[str] = MULTI_TENANT_PRACTICE_AREAS | DOMAIN_PRACTICE_AREAS | {""}
 
 APPEALS_COMMITTEE_SUBTYPES: set[str] = {
     "building_permit",
     "betterment_levy",
     "compensation_197",
+    # בל"מ — בקשה להארכת מועד להגשת ערר. מסלולים נפרדים לפי domain:
+    "extension_request_building_permit",  # 1xxx — סעיף 152, 30 ימים
+    "extension_request_betterment_levy",  # 8xxx — סעיף 14 לתוספת ג', 45 ימים
+    "extension_request_compensation",     # 9xxx — סעיף 198(ד), 30 ימים
     "unknown",
 }
 
+# בל"מ subtypes — קל לזהות ע"י prefix
+BLAM_SUBTYPES: set[str] = {
+    "extension_request_building_permit",
+    "extension_request_betterment_levy",
+    "extension_request_compensation",
+}
+
+# מיפוי domain → בל"מ subtype
+_DOMAIN_TO_BLAM_SUBTYPE: dict[str, str] = {
+    "rishuy_uvniya": "extension_request_building_permit",
+    "betterment_levy": "extension_request_betterment_levy",
+    "compensation_197": "extension_request_compensation",
+}
+
+# מיפוי first-digit → בל"מ subtype (אותו מבנה כמו _APPEALS_COMMITTEE_DIGIT_TO_SUBTYPE)
+_APPEALS_COMMITTEE_DIGIT_TO_BLAM = {
+    "1": "extension_request_building_permit",
+    "8": "extension_request_betterment_levy",
+    "9": "extension_request_compensation",
+}
+
 DEFAULT_PRACTICE_AREA = "appeals_committee"
 
 # Subtypes per practice_area (extend when adding domains)
@@ -70,9 +98,11 @@ SUBTYPES_BY_AREA: dict[str, set[str]] = {
     "national_insurance": {"unknown"},
     "labor_law": {"unknown"},
     # Domain values — subtype is implicit in the value itself
-    "rishuy_uvniya": {"building_permit", "unknown"},
-    "betterment_levy": {"betterment_levy", "unknown"},
-    "compensation_197": {"compensation_197", "unknown"},
+    "rishuy_uvniya": {"building_permit", "extension_request_building_permit", "unknown"},
+    "betterment_levy": {"betterment_levy", "extension_request_betterment_levy", "unknown"},
+    "compensation_197": {"compensation_197", "extension_request_compensation", "unknown"},
+    # Empty (unclassified) — allow any of the appeals_committee subtypes
+    "": APPEALS_COMMITTEE_SUBTYPES,
 }
 
 # Mapping: (multi_tenant_pa, appeal_subtype) → domain_pa
@@ -80,9 +110,39 @@ _SUBTYPE_TO_DOMAIN: dict[str, str] = {
     "building_permit": "rishuy_uvniya",
     "betterment_levy": "betterment_levy",
     "compensation_197": "compensation_197",
+    "extension_request_building_permit": "rishuy_uvniya",
+    "extension_request_betterment_levy": "betterment_levy",
+    "extension_request_compensation": "compensation_197",
 }
 
 
+# Regex לזיהוי "בקשה להארכת מועד" בנושא הערר (subject) —
+# וריאציות נפוצות. case-insensitive, מתחשב במרכאות חכמות/רגילות.
+_BLAM_SUBJECT_PATTERNS = (
+    re.compile(r"בקשה\s+להארכת\s+מועד", re.IGNORECASE),
+    re.compile(r"בל[\"״״]מ", re.IGNORECASE),   # בל"מ עם quote variants
+    re.compile(r"הארכת\s+מועד\s+להגשת", re.IGNORECASE),
+)
+
+
+def is_blam_subject(subject: str) -> bool:
+    """True iff subject indicates a בל"מ (extension-of-time request).
+
+    מזהה: "בקשה להארכת מועד", "בל\"מ", "הארכת מועד להגשת..."
+
+    Examples:
+        >>> is_blam_subject("בל\"מ אלחנן ברלינגר נ' לינדאב")
+        True
+        >>> is_blam_subject("בקשה להארכת מועד להגשת ערר")
+        True
+        >>> is_blam_subject("היתר בנייה ברחוב X")
+        False
+    """
+    if not subject:
+        return False
+    return any(p.search(subject) for p in _BLAM_SUBJECT_PATTERNS)
+
+
 def to_db_practice_area(practice_area: str, appeal_subtype: str = "") -> str:
     """Convert a multi-tenant practice_area + appeal_subtype to the
     domain value stored in DB columns (case_law/cases).
@@ -120,14 +180,28 @@ _CASE_NUM = re.compile(r"(?:ARAR[-\s]*\d{2}[-\s]*(?:\d{2}[-\s]*)?)(\d{4})", re.I
 _PLAIN_NUM = re.compile(r"(\d{4})")
 
 
+_DOMAIN_TO_SUBTYPE: dict[str, str] = {
+    "rishuy_uvniya": "building_permit",
+    "betterment_levy": "betterment_levy",
+    "compensation_197": "compensation_197",
+}
+
+
 def derive_subtype(case_number: str, practice_area: str = DEFAULT_PRACTICE_AREA) -> str:
     """Infer the appeal_subtype from case_number.
 
-    For appeals_committee, the convention is:
+    For appeals_committee (axis A), the convention is:
       1xxx → building_permit, 8xxx → betterment_levy, 9xxx → compensation_197.
 
+    For domain values (axis B — rishuy_uvniya/betterment_levy/compensation_197),
+    the subtype is implicit in the practice_area itself — we map directly
+    without parsing the case number.
+
     Handles multiple formats: ARAR-25-8126, 8126/25, 1170, ערר 1024-25.
     """
+    # Axis B: practice_area is already a domain value — map directly.
+    if practice_area in DOMAIN_PRACTICE_AREAS:
+        return _DOMAIN_TO_SUBTYPE.get(practice_area, "unknown")
     if practice_area != "appeals_committee":
         return "unknown"
     cn = case_number or ""
@@ -142,6 +216,82 @@ def derive_subtype(case_number: str, practice_area: str = DEFAULT_PRACTICE_AREA)
     return _APPEALS_COMMITTEE_DIGIT_TO_SUBTYPE.get(first_digit, "unknown")
 
 
+def derive_subtype_with_blam(
+    case_number: str,
+    subject: str = "",
+    practice_area: str = DEFAULT_PRACTICE_AREA,
+) -> str:
+    """Like ``derive_subtype()`` but also detects בל"מ from the subject.
+
+    If ``subject`` indicates a בקשה להארכת מועד, the returned subtype is
+    one of the ``extension_request_*`` values (chosen per case_number /
+    practice_area). Otherwise behaviour matches ``derive_subtype()``.
+
+    Examples:
+        >>> derive_subtype_with_blam("1017-03-26", "בל\"מ ברלינגר נ' לינדאב")
+        'extension_request_building_permit'
+        >>> derive_subtype_with_blam("8500-25", "בקשה להארכת מועד")
+        'extension_request_betterment_levy'
+        >>> derive_subtype_with_blam("1033-25", "ערר על החלטת ועדה")
+        'building_permit'
+    """
+    base = derive_subtype(case_number, practice_area)
+    if not is_blam_subject(subject):
+        return base
+    # subject says it's בל"מ — return the matching extension_request_* variant.
+    # For domain practice_area (axis B), use the direct mapping.
+    if practice_area in DOMAIN_PRACTICE_AREAS:
+        return _DOMAIN_TO_BLAM_SUBTYPE.get(practice_area, base)
+    # For appeals_committee (axis A), derive from case_number digit.
+    if practice_area == "appeals_committee":
+        cn = case_number or ""
+        m = _CASE_NUM.search(cn) or _PLAIN_NUM.search(cn)
+        if m:
+            first_digit = m.group(1)[0]
+            blam = _APPEALS_COMMITTEE_DIGIT_TO_BLAM.get(first_digit)
+            if blam:
+                return blam
+    return base
+
+
+def is_blam_subtype(appeal_subtype: str) -> bool:
+    """True iff appeal_subtype is one of the extension_request_* variants.
+
+    Useful for UI badges and routing logic that need to detect בל"מ cases
+    regardless of which domain they belong to.
+    """
+    return appeal_subtype in BLAM_SUBTYPES
+
+
+def derive_domain_practice_area(case_number: str) -> str:
+    """Map a case_number prefix to a domain practice_area (axis B).
+
+    Returns:
+        ``"rishuy_uvniya"`` for 1xxx, ``"betterment_levy"`` for 8xxx,
+        ``"compensation_197"`` for 9xxx, or ``""`` when the prefix is
+        unrecognized (caller decides the fallback).
+
+    Examples:
+        >>> derive_domain_practice_area("8126/25")
+        'betterment_levy'
+        >>> derive_domain_practice_area("1170")
+        'rishuy_uvniya'
+        >>> derive_domain_practice_area("ARAR-24-01-9007")
+        'compensation_197'
+        >>> derive_domain_practice_area("foo")
+        ''
+    """
+    cn = case_number or ""
+    m = _CASE_NUM.search(cn) or _PLAIN_NUM.search(cn)
+    if not m:
+        return ""
+    first_digit = m.group(1)[0]
+    subtype = _APPEALS_COMMITTEE_DIGIT_TO_SUBTYPE.get(first_digit)
+    if not subtype:
+        return ""
+    return _SUBTYPE_TO_DOMAIN.get(subtype, "")
+
+
 # ── Validation ─────────────────────────────────────────────────────
 
 
@@ -164,6 +314,20 @@ def validate(practice_area: str, appeal_subtype: str | None) -> None:
 
 def is_override(case_number: str, practice_area: str, appeal_subtype: str) -> bool:
     """True iff the user-supplied subtype disagrees with what derive_subtype
-    would have produced (and the derived value is not 'unknown')."""
+    would have produced (and the derived value is not 'unknown').
+
+    Note: בל"מ variants (extension_request_*) are NOT considered overrides
+    of their parent domain — extension_request_building_permit on a 1xxx
+    case is consistent with the case-number convention.
+    """
     derived = derive_subtype(case_number, practice_area)
-    return derived != "unknown" and derived != appeal_subtype
+    if derived == "unknown":
+        return False
+    if derived == appeal_subtype:
+        return False
+    # בל"מ variants of the same domain are not overrides.
+    if appeal_subtype in BLAM_SUBTYPES:
+        # extension_request_building_permit ↔ building_permit (1xxx) — same domain
+        if _SUBTYPE_TO_DOMAIN.get(appeal_subtype) == _SUBTYPE_TO_DOMAIN.get(derived):
+            return False
+    return True