Add CMPA (betterment levy) training support and update methodology

Support ingestion of betterment levy (היטל השבחה) decisions into a
separate training corpus (CMPA). Key changes:

- Add .doc file extraction via LibreOffice conversion in extractor
- Add practice_area/appeal_subtype columns to style_corpus table
- Route training files to cmp/ or cmpa/ subdirs based on appeal subtype
- Fix derive_subtype to handle ARAR-YY-NNNN format (was matching year digit)
- Expose practice_area/appeal_subtype params in MCP upload_training tool
- Add appeal_subtype filter to analyze_style for per-type style analysis
- Update betterment levy methodology in lessons.py: checklist (from generic
  to corpus-based), opening/closing strategies, and discussion rules

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

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

@@ -104,6 +104,8 @@ CREATE TABLE IF NOT EXISTS style_corpus (
     summary TEXT DEFAULT '',
     outcome TEXT DEFAULT '',
     key_principles JSONB DEFAULT '[]',
+    practice_area TEXT DEFAULT 'appeals_committee',
+    appeal_subtype TEXT DEFAULT '',
     created_at TIMESTAMPTZ DEFAULT now()
 );
 
@@ -159,6 +161,10 @@ 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 '';
 
+-- הרחבת style_corpus עם practice_area / appeal_subtype
+ALTER TABLE style_corpus ADD COLUMN IF NOT EXISTS practice_area TEXT DEFAULT 'appeals_committee';
+ALTER TABLE style_corpus ADD COLUMN IF NOT EXISTS appeal_subtype TEXT DEFAULT '';
+
 -- טבלת qa_results
 CREATE TABLE IF NOT EXISTS qa_results (
     id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
@@ -882,6 +888,8 @@ async def add_to_style_corpus(
     summary: str = "",
     outcome: str = "",
     key_principles: list[str] | None = None,
+    practice_area: str = "appeals_committee",
+    appeal_subtype: str = "",
 ) -> UUID:
     pool = await get_pool()
     corpus_id = uuid4()
@@ -889,11 +897,13 @@ async def add_to_style_corpus(
         await conn.execute(
             """INSERT INTO style_corpus
                (id, document_id, decision_number, decision_date,
-                subject_categories, full_text, summary, outcome, key_principles)
-               VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)""",
+                subject_categories, full_text, summary, outcome, key_principles,
+                practice_area, appeal_subtype)
+               VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11)""",
             corpus_id, document_id, decision_number, decision_date,
             json.dumps(subject_categories), full_text, summary, outcome,
             json.dumps(key_principles or []),
+            practice_area, appeal_subtype,
         )
     return corpus_id