Add: Decisive appraiser (שמאי מכריע) search via gov.il public API

Adds a new MCP tool `search_decisive_appraisals` that queries the
Ministry of Justice public registry (~30K published decisions) by
block (גוש), plot (חלקה), appraiser name, committee, decision/publicity
date ranges, or free text — and returns metadata + direct PDF URLs.

Implementation notes:
- New `nadlan_mcp/govil/` package, parallel to `nadlan_mcp/govmap/`,
  for gov.il APIs that are not Govmap. Pydantic v2 models match the
  upstream PascalCase response via aliases.
- Upstream sits behind an F5 WAF that rejects standard `requests`;
  uses `curl_cffi` with Chrome 120 impersonation to traverse it.
- Static `x-client-id` header (issued to the gov.il SPA, public, visible
  in any DevTools session) is required by the gateway — without it
  every call returns a generic 500.
- 14 unit tests cover model parsing, body shape, pagination, and the
  500-is-fatal contract (configuration error, not retryable).

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

nadlan_mcp/govil/__init__.py

@@ -0,0 +1,21 @@
+"""
+Israeli government open API (gov.il) clients.
+
+This package provides clients for gov.il public APIs distinct from Govmap —
+notably the Ministry of Justice "Decisive Appraiser" search service that
+exposes published decisions of certified property appraisers.
+"""
+
+from .client import DecisiveAppraiserClient
+from .models import (
+    AppraisalDecision,
+    AppraisalDocument,
+    DecisiveAppraiserSearchResponse,
+)
+
+__all__ = [
+    "DecisiveAppraiserClient",
+    "AppraisalDecision",
+    "AppraisalDocument",
+    "DecisiveAppraiserSearchResponse",
+]