fix: address review — python smoke caller, contract prose, fixture header hygiene

ds-review-bot findings: the packaged Python runtime smoke's scripted
run_code call gains the required description; the ToolDefinition JSDoc
and the Code Mode foundation note (both languages, pair re-recorded) now
state both required parameters; the cordis-dynamic-toolchain fixture's
request/header line is re-compacted so the header-scrub hygiene guard
passes (my earlier patch had re-spaced it). The TUI terminal fixture was
already regenerated from keyless replay in the previous commit.

scripts/smoke-python-runtime.py

@@ -151,7 +151,11 @@ def completion_chunks(body: dict[str, object]) -> list[dict[str, object]]:
         )
     if prompt == CODE_PROMPT:
         assert_advertised_tool(body, "run_code")
-        return tool_call_chunks("call-code-worker", "run_code", {"code": "return 6 * 7"})
+        return tool_call_chunks(
+            "call-code-worker",
+            "run_code",
+            {"code": "return 6 * 7", "description": "Compute the smoke value"},
+        )
     if prompt == WORKFLOW_PROMPT:
         assert_advertised_tool(body, "workflow")
         return tool_call_chunks(