feat(corpus): Stage A — corpus tagging fixes + prevention layer

מתקן את הבאג של תיוג שגוי לועדות ערר ומונע חזרתו:

**Code changes:**
* New MCP tool `internal_decision_upload` (chair_name+district required)
  — sole supported path for ingesting committee decisions; tags
  source_kind='internal_committee' automatically.
* Citation guard in `precedent_library_upload` rejects citations starting
  with "ערר" or "בל\"מ" with a directive to use internal_decision_upload.
* `practice_area.py` taxonomy unification: PRACTICE_AREAS now accepts
  both multi-tenant (appeals_committee/national_insurance/labor_law)
  and domain (rishuy_uvniya/betterment_levy/compensation_197) values.
  New helper `to_db_practice_area(multi_tenant, subtype) -> domain`.

**Agent docs:**
* legal-researcher (+5K): upload-tool decision flowchart, code samples
  per source_kind, district enum (ירושלים/מרכז/תל אביב/צפון/דרום/חיפה/ארצי)
* legal-ceo, legal-analyst, legal-writer, legal-qa, HEARTBEAT — taxonomy
  awareness + source_kind-aware citation patterns + research_complete
  as valid status.
* Fixed two pre-existing wrong practice_area values in examples
  (histael_hashbacha→betterment_levy, pitsuim_197→compensation_197).

Closes TaskMaster #30(parts), #38(parts), #39 (root cause).
DB-side backfill + CHECK constraints applied directly via psql:
* 11 cases.practice_area corrected (1xxx→rishuy, 8xxx→betterment)
* 6 case_law records reclassified external_upload→internal_committee
  with inferred district
* 6 chair_name backfilled from full_text (5 שרית אריאלי + 1 דפנה תמיר)
* 88 new halachot extracted for newly-uploaded precedents
  (אנטרים + ירושלים שקופה 1112/22 + אגא וכט)
* CHECK constraints: cases.practice_area enum, case_law internal⇒district

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

mcp-server/src/legal_mcp/server.py

@@ -53,6 +53,7 @@ mcp = FastMCP(
 from legal_mcp.tools import (  # noqa: E402
     cases, documents, search, drafting, workflow, precedents,
     precedent_library as plib,
+    internal_decisions as int_tools,
 )
 
 
@@ -662,6 +663,46 @@ async def internal_decision_enrich(
     return _json.dumps(result, ensure_ascii=False, indent=2)
 
 
+@mcp.tool()
+async def internal_decision_upload(
+    file_path: str,
+    case_number: str,
+    chair_name: str,
+    district: str,
+    case_name: str = "",
+    court: str = "",
+    decision_date: str = "",
+    practice_area: str = "",
+    appeal_subtype: str = "",
+    subject_tags: list[str] | None = None,
+    summary: str = "",
+    is_binding: bool = False,
+) -> str:
+    """העלאת החלטה של ועדת ערר (internal_committee) לקורפוס הסמכותי.
+
+    שדות חובה: file_path, case_number, chair_name, district.
+    שמירת ההחלטה עוברת דרך ingest_internal_decision — תויג source_kind='internal_committee' אוטומטית.
+    district תקין: ירושלים / מרכז / תל אביב / צפון / דרום / חיפה / ארצי.
+
+    בניגוד ל-precedent_library_upload (שתמיד שומר external_upload),
+    הכלי הזה הוא הנתיב המוסמך להחלטות ועדת ערר ומכריח chair_name+district.
+    """
+    return await int_tools.internal_decision_upload(
+        file_path=file_path,
+        case_number=case_number,
+        chair_name=chair_name,
+        district=district,
+        case_name=case_name,
+        court=court,
+        decision_date=decision_date,
+        practice_area=practice_area,
+        appeal_subtype=appeal_subtype,
+        subject_tags=subject_tags,
+        summary=summary,
+        is_binding=is_binding,
+    )
+
+
 @mcp.tool()
 async def record_chair_feedback(
     case_number: str,