feat: stabilize category rule operations

approve dcy-001 and add REQ/BAT evidence

pass selected DB path through Streamlit rule actions

expose delete_category_rule MCP tool

add category rule deletion regression

tests/test_category_rule_filters.py

@@ -103,3 +103,34 @@ def test_update_category_rule_allows_condition_edits(tmp_path):
     assert rule["amount_max"] == 150000
     assert rule["day_of_month"] == 10
     assert rule["active"] is False
+
+
+def test_delete_category_rule_removes_rule_and_reports_missing_ids(tmp_path):
+    db_path = str(tmp_path / "ledger.sqlite3")
+    service.health_check(db_path)
+    created = service.create_category_rule(
+        match_field="merchant",
+        match_type="contains",
+        pattern="삭제대상",
+        transaction_type="expense",
+        category="쇼핑",
+        subcategory="생활용품",
+        db_path=db_path,
+    )
+    assert created["success"] is True
+    rule_id = created["rule"]["id"]
+
+    before = service.list_category_rules(active_only=False, db_path=db_path)
+    assert any(rule["id"] == rule_id for rule in before["rules"])
+
+    deleted = service.delete_category_rule(rule_id, db_path=db_path)
+    assert deleted == {"success": True, "deleted_rule_id": rule_id}
+
+    after_all = service.list_category_rules(active_only=False, db_path=db_path)
+    after_active = service.list_category_rules(active_only=True, db_path=db_path)
+    assert all(rule["id"] != rule_id for rule in after_all["rules"])
+    assert all(rule["id"] != rule_id for rule in after_active["rules"])
+
+    missing = service.delete_category_rule(rule_id, db_path=db_path)
+    assert missing["success"] is False
+    assert missing["error_code"] == "not_found"