fix(sdk-minimal): make the SDK model argument authoritative

Stop narrowing the standalone DeepSeek adapter to a DSH_MODEL-derived one-entry catalog. The direct adapter already accepts model ids outside its advisory catalog, so retain only the DSH_CONTEXT_WINDOW fallback and let the JSON-RPC initialize model be the single runtime selection.

Remove model mirroring from minimal.py and the packaged smoke. The keyless process now initializes deepseek-v4-pro without DSH_MODEL, while the packaged scenario continues to use its unlisted smoke-model; together they prove both cataloged and arbitrary SDK model arguments reach the adapter directly.

Update the bundle, tutorial, SDK/example references, and owning Agent Notes to keep DSH_MODEL only as minimal.py's optional default input, never as a second value callers must synchronize.

scripts/smoke-python-runtime.py

@@ -978,9 +978,6 @@ def smoke_sdk_minimal(base_url: str, executable: Path, update_snapshots: bool) -
             dsh_bin=str(executable),
             dsh_home=str(dsh_home),
             profile="sdk-minimal",
-            env={
-                "DSH_MODEL": "smoke-model",
-            },
             api_key="sk-keyless-smoke",
             base_url=base_url,
             request_timeout_seconds=60,