feat(retrieval): require practice_area only for internal/cases; enable searchable filter + health visibility (GAP-13, FU-2a)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

mcp-server/tests/test_idempotent_ingest.py

@@ -70,6 +70,15 @@ def test_compute_searchable_false_without_core_fields():
     assert db._compute_searchable(row, has_embedded_chunk=True) is False
 
 
+def test_compute_searchable_external_allows_empty_practice_area():
+    # External precedents (e.g. בג"ץ) are cross-domain — empty practice_area
+    # must NOT disqualify them, as long as the rest of the contract holds.
+    row = _complete_row()
+    row["source_kind"] = "external_upload"
+    row["practice_area"] = ""
+    assert db._compute_searchable(row, has_embedded_chunk=True) is True
+
+
 # ── ingest wires in recompute_searchable (both types) ──────────────────
 def test_ingest_calls_recompute_searchable(monkeypatch, tmp_path):
     calls = {"recompute": [], "meta": [], "hal": []}