feat(proceeding-type): explicit ערר/בל"מ field for cases + corpus

Same case_number can exist as both a regular appeal (ערר) and an
extension-of-time request (בל"מ), and we were inferring the difference
from appeal_subtype prefixes — fragile, and case-number lookups
weren't disambiguated. Now stored as a first-class field on both
case_law (corpus) and cases (live cases), with partial unique indexes
on (case_number, proceeding_type).

- SCHEMA_V15: column + CHECK constraints + backfill from
  appeal_subtype LIKE 'extension_request_%' + partial unique indexes
  replace the old global UNIQUE(case_number).
- derive_proceeding_type() centralizes the inference rule
  (extension_request_* → בל"מ; subject regex fallback; default ערר).
- Metadata extractor prompt asks Claude to populate the new field
  explicitly; apply_to_record writes it for internal_committee rows.
- internal_decision_upload, case_create, case_update accept an
  optional proceeding_type; FastAPI request models expose it.
- Wizard + edit dialog get a sided Select; case header renders the
  resolved label (ערר / בל"מ).
- Uploaded the 2 staged בל"מ decisions on betterment levy:
  8126/24 (סופר נוח, 13 chunks), 8047/23 (הרנון, 48 chunks).

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

scripts/upload_blam_decisions.py

@@ -0,0 +1,60 @@
+"""One-shot uploader for the 2 new בל"מ decisions Chaim staged in
+data/precedents/incoming/. Bypasses MCP because the running MCP server
+was started before SCHEMA_V15 + proceeding_type wiring landed.
+
+Run from /home/chaim/legal-ai with the venv:
+    POSTGRES_URL=... .venv/bin/python scripts/upload_blam_decisions.py
+"""
+
+import asyncio
+import os
+import sys
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "mcp-server", "src"))
+
+from legal_mcp.services import internal_decisions as svc
+
+DECISIONS = [
+    {
+        "file_path": "/home/chaim/legal-ai/data/precedents/incoming/ARAR-24-8126.pdf",
+        "case_number": "8126/24",
+        "chair_name": "דפנה תמיר",
+        "district": "ירושלים",
+        "case_name": "הוועדה המקומית ירושלים נ' סופר נוח",
+        "court": "ועדת הערר לתכנון ובנייה — מחוז ירושלים",
+        "decision_date": "2024-07-07",
+        "practice_area": "betterment_levy",
+        "appeal_subtype": "extension_request_betterment_levy",
+        "proceeding_type": 'בל"מ',
+        "subject_tags": ["בקשה_להארכת_מועד", "היטל_השבחה"],
+        "summary": "",
+        "is_binding": False,
+    },
+    {
+        "file_path": "/home/chaim/legal-ai/data/precedents/incoming/ARAR-23-8047-3.docx",
+        "case_number": "8047/23",
+        "chair_name": "דפנה תמיר",
+        "district": "ירושלים",
+        "case_name": 'עזבון אליהו הרנון ז"ל נ\' הוועדה המקומית ירושלים',
+        "court": "ועדת הערר לתכנון ובנייה — מחוז ירושלים",
+        "decision_date": "2025-09-29",
+        "practice_area": "betterment_levy",
+        "appeal_subtype": "extension_request_betterment_levy",
+        "proceeding_type": 'בל"מ',
+        "subject_tags": ["בקשה_להארכת_מועד", "היטל_השבחה"],
+        "summary": "",
+        "is_binding": False,
+    },
+]
+
+
+async def main():
+    for d in DECISIONS:
+        print(f"→ uploading {d['case_number']} ({d['proceeding_type']})")
+        result = await svc.ingest_internal_decision(**d)
+        print(f"  ✓ case_law_id={result.get('case_law_id')} chunks={result.get('chunks')}")
+    print("done.")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())