🐛 fix(tsl-syntax): gate lookup mode boosts

test/test_tsl_syntax_lookup.py

@@ -35,20 +35,28 @@ class TslSyntaxLookupTests(unittest.TestCase):
         result = lookup.query_sections("数组下标", "explain", limit=3)
         self.assertEqual(result.prelude, [])
 
-    def test_no_match_returns_exit_code_two(self):
-        completed = subprocess.run(
-            [
-                sys.executable,
-                str(SCRIPT),
-                "--query",
-                "不存在的孤立语法词xyz",
-                "--mode",
-                "explain",
-            ],
-            capture_output=True,
-            text=True,
-        )
-        self.assertEqual(completed.returncode, 2)
+    def test_no_match_returns_exit_code_two_in_every_mode(self):
+        for mode in ("write", "diagnose", "explain"):
+            with self.subTest(mode=mode):
+                completed = subprocess.run(
+                    [
+                        sys.executable,
+                        str(SCRIPT),
+                        "--query",
+                        "不存在的孤立语法词xyz",
+                        "--mode",
+                        mode,
+                    ],
+                    capture_output=True,
+                    text=True,
+                    encoding="utf-8",
+                )
+                self.assertEqual(completed.returncode, 2)
+
+    def test_write_identifier_query_keeps_required_context(self):
+        result = lookup.query_sections("varByRef 命名参数", "write", limit=5)
+        prelude_pages = {section.page.name for section in result.prelude}
+        self.assertEqual(prelude_pages, {"01_quickstart.md", "02_core_model.md"})
 
     def test_check_rejects_unknown_code_block_identity(self):
         with tempfile.TemporaryDirectory() as tmp_dir: