Follow-up #601: route scripts through shared LLM adapter

scripts/langchain/followup_issue_generator.py

@@ -908,19 +908,22 @@ def _parse_checklist(lines: list[str]) -> list[str]:
 def _get_llm_client(reasoning: bool = False) -> tuple[Any, str] | None:
     """Get LLM client using slot order with optional reasoning model override."""
     try:
-        from tools.langchain_client import build_chat_client
+        from scripts.langchain._llm_client import build_client
     except ImportError as e:
-        print(f"Warning: langchain_client not available: {e}", file=sys.stderr)
-        return None
+        try:
+            from _llm_client import build_client
+        except ImportError:
+            print(f"Warning: shared LLM client adapter not available: {e}", file=sys.stderr)
+            return None
 
     if reasoning:
         model = os.environ.get("FOLLOWUP_REASONING_MODEL", "o3-mini")
-        resolved = build_chat_client(model=model, provider="openai")
+        resolved = build_client(model=model, provider="openai")
         if not resolved:
-            resolved = build_chat_client()
+            resolved = build_client()
     else:
         model = os.environ.get("FOLLOWUP_MODEL", "gpt-5.4")
-        resolved = build_chat_client(model=model)
+        resolved = build_client(model=model)
 
     if not resolved:
         print("Warning: No LLM API keys found", file=sys.stderr)

scripts/langchain/progress_reviewer.py

@@ -427,11 +427,14 @@ def review_progress_with_llm(
         rounds_without_completion,
     )
     try:
-        from tools.langchain_client import build_chat_client
+        from scripts.langchain._llm_client import build_client
     except ImportError:
-        build_chat_client = None
+        try:
+            from _llm_client import build_client
+        except ImportError:
+            build_client = None
 
-    resolved = build_chat_client(model=model) if build_chat_client else None
+    resolved = build_client(model=model) if build_client else None
     if not resolved:
         score, aligned, unaligned = heuristic_alignment_check(
             acceptance_criteria, recent_commits, files_changed

tests/tools/test_llm_client_single_source.py

@@ -70,3 +70,18 @@ def fake_build_chat_client(**kwargs: object) -> object:
             "force_openai": False,
         }
     ]
+
+
+def test_scripts_do_not_bypass_shared_llm_client_adapter() -> None:
+    for path in (REPO_ROOT / "scripts").rglob("*.py"):
+        if path.as_posix().endswith("scripts/langchain/_llm_client.py"):
+            continue
+        source = path.read_text(encoding="utf-8")
+        tree = ast.parse(source, filename=path.as_posix())
+        for node in ast.walk(tree):
+            if (
+                isinstance(node, ast.ImportFrom)
+                and node.module == "tools.langchain_client"
+                and any(alias.name == "build_chat_client" for alias in node.names)
+            ):
+                raise AssertionError(path.relative_to(REPO_ROOT).as_posix())