test(tool-search): make salvage-seam tests order- and stem-robust

Two interaction seams between the #92693 salvage (merged as #95050) and
this branch: the source-label indexing test now compares in token space
(the stemmer shortens 'catalogsource' to 'catalogsourc'), and the
unregistered-core-name describe test forces the unregistered condition
via monkeypatch instead of depending on which sibling test file imported
model_tools first.

tests/tools/test_deferral_fixes.py

@@ -297,9 +297,14 @@ class TestSourceNameIndexing:
                 _td("mcp__catalogsource__native_action", "Perform a native action."),
                 _td("plugin_action", "Perform a plugin action."),
             ])
+            # Compare in token space: the tokenizer may stem (e.g.
+            # "catalogsource" -> "catalogsourc"), and the contract is that
+            # the label lands in the document exactly once either way.
+            from tools.tool_search import _tokenize
+            label_token = _tokenize(source_label)[0]
             tokens_by_name = {entry.name: entry._tokens for entry in catalog}
-            assert tokens_by_name[names[0]].count(source_label) == 1
-            assert tokens_by_name[names[1]].count(source_label) == 1
+            assert tokens_by_name[names[0]].count(label_token) == 1
+            assert tokens_by_name[names[1]].count(label_token) == 1
         finally:
             for name in names:
                 registry.deregister(name)

tests/tools/test_tool_search_multiquery.py

@@ -422,9 +422,22 @@ class TestBatchedDescribe:
         assert result["not_found"] == ["mcp__linear__does_not_exist_zzz"]
         assert "errors" not in result
 
-    def test_unregistered_core_name_is_not_found(self, issue_defs):
+    def test_unregistered_core_name_is_not_found(self, issue_defs, monkeypatch):
+        from tools import registry as registry_module
         from tools.tool_search import ToolSearchConfig, dispatch_tool_describe
 
+        # The intent: a name that is NOT registered lands in not_found, even
+        # when it looks like a core tool. Whether "terminal" is registered in
+        # this process depends on which test files imported model_tools
+        # earlier, so force the unregistered condition instead of relying on
+        # collection order.
+        real_get_entry = registry_module.registry.get_entry
+        monkeypatch.setattr(
+            registry_module.registry,
+            "get_entry",
+            lambda name: None if name == "terminal" else real_get_entry(name),
+        )
+
         result = json.loads(dispatch_tool_describe(
             {"names": ["terminal", "mq_linear_create_issue"]},
             current_tool_defs=issue_defs,