diff --git a/pyproject.toml b/pyproject.toml
index 6f805a7f..c3cab12c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -182,6 +182,7 @@ extend-exclude = ["src/seclab_taskflow_agent/mcp_servers/codeql/jsonrpyc/"]
 ignore = [
   # Style choices — deliberate project conventions
   "EM101",    # Exception string literals
+  "G004",     # Logging f-strings
   "EM102",    # Exception f-strings
   "T201",     # print() used for user output
   "TRY003",   # Raise with inline message strings
diff --git a/src/seclab_taskflow_agent/models.py b/src/seclab_taskflow_agent/models.py
index eff05ee6..22c4d692 100644
--- a/src/seclab_taskflow_agent/models.py
+++ b/src/seclab_taskflow_agent/models.py
@@ -66,9 +66,8 @@ def _normalise_version(cls, v: Any) -> str:
     @classmethod
     def _validate_version(cls, v: str) -> str:
         if v != SUPPORTED_VERSION:
-            raise ValueError(
-                f"Unsupported version: {v}. Only version {SUPPORTED_VERSION} is supported."
-            )
+            msg = f"Unsupported version: {v}. Only version {SUPPORTED_VERSION} is supported."
+            raise ValueError(msg)
         return v