Fix practice_area/appeal_subtype regression in search and case creation

The merge of ui-rewrite removed these parameters from db.search_similar()
and db.create_case() but left the callers passing them, causing TypeError
on any corpus search. Restores the parameters and adds schema migration.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

mcp-server/src/legal_mcp/services/db.py

@@ -156,6 +156,8 @@ ALTER TABLE decisions ADD COLUMN IF NOT EXISTS outcome_reasoning TEXT DEFAULT ''
 
 -- הרחבת cases עם appeal_type (אם לא קיים)
 ALTER TABLE cases ADD COLUMN IF NOT EXISTS appeal_type TEXT DEFAULT '';
+ALTER TABLE cases ADD COLUMN IF NOT EXISTS practice_area TEXT DEFAULT 'appeals_committee';
+ALTER TABLE cases ADD COLUMN IF NOT EXISTS appeal_subtype TEXT DEFAULT '';
 
 -- טבלת qa_results
 CREATE TABLE IF NOT EXISTS qa_results (
@@ -467,6 +469,8 @@ async def create_case(
     hearing_date: date | None = None,
     notes: str = "",
     expected_outcome: str = "",
+    practice_area: str = "appeals_committee",
+    appeal_subtype: str = "",
 ) -> dict:
     pool = await get_pool()
     case_id = uuid4()
@@ -474,13 +478,15 @@ async def create_case(
         await conn.execute(
             """INSERT INTO cases (id, case_number, title, appellants, respondents,
                subject, property_address, permit_number, committee_type,
-               hearing_date, notes, expected_outcome)
-               VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12)""",
+               hearing_date, notes, expected_outcome,
+               practice_area, appeal_subtype)
+               VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14)""",
             case_id, case_number, title,
             json.dumps(appellants or []),
             json.dumps(respondents or []),
             subject, property_address, permit_number, committee_type,
             hearing_date, notes, expected_outcome,
+            practice_area, appeal_subtype,
         )
     return await get_case(case_id)
 
@@ -809,6 +815,8 @@ async def search_similar(
     limit: int = 10,
     case_id: UUID | None = None,
     section_type: str | None = None,
+    practice_area: str | None = None,
+    appeal_subtype: str | None = None,
 ) -> list[dict]:
     """Cosine similarity search on document chunks."""
     pool = await get_pool()
@@ -824,6 +832,14 @@ async def search_similar(
         conditions.append(f"dc.section_type = ${param_idx}")
         params.append(section_type)
         param_idx += 1
+    if practice_area:
+        conditions.append(f"c.practice_area = ${param_idx}")
+        params.append(practice_area)
+        param_idx += 1
+    if appeal_subtype:
+        conditions.append(f"c.appeal_subtype = ${param_idx}")
+        params.append(appeal_subtype)
+        param_idx += 1
 
     where = f"WHERE {' AND '.join(conditions)}" if conditions else ""