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/tools/drafting.py

@@ -454,11 +454,16 @@ async def save_block_content(case_number: str, block_id: str, content: str) -> s
         return str(e)
 
 
-async def analyze_style() -> str:
-    """הרצת ניתוח סגנון על קורפוס ההחלטות של דפנה. מחלץ דפוסי כתיבה ושומר אותם."""
+async def analyze_style(appeal_subtype: str = "") -> str:
+    """הרצת ניתוח סגנון על קורפוס ההחלטות של דפנה. מחלץ דפוסי כתיבה ושומר אותם.
+
+    Args:
+        appeal_subtype: סינון לפי סוג ערר (building_permit / betterment_levy / compensation_197).
+                        ריק = כל ההחלטות.
+    """
     from legal_mcp.services.style_analyzer import analyze_corpus
 
-    result = await analyze_corpus()
+    result = await analyze_corpus(appeal_subtype)
     return json.dumps(result, ensure_ascii=False, indent=2)