fix(synthbench): substitute runnable model_id from leaderboard rows (sy-i7a)

[openclaw-dv]

Summary

When a top SynthBench row's model field is a display label (e.g.
"SynthPanel (Gemini Flash Lite)") the prior fix (sy-kh3, #521) refused
it and fell back to the default model — which, with only OpenRouter
credentials present, lands on openrouter/auto. But SynthBench #297 now
publishes a runnable id in the row's model_id (e.g.
"google/gemini-2.5-flash-lite"). Hermes v1.5.4 dogfood re-reported #519:
refuse-and-fallback works, but the runnable model_id is ignored.

Fix

• _runnable_id_from_row() — prefer entry["model_id"], joined with entry["provider_id"] as "<provider_id>/<model_id>" when model_id is a bare slug. A model_id that is itself a display label is ignored so we never reintroduce the non-runnable-stamping failure.
• recommend() — when the display model is non-runnable, prefer the runnable model_id (authoritative) over the config_id base-model heuristic; fall back to config_id inference only when no model_id exists; refuse only when neither yields a runnable id. runnable=True now lets the CLI stamp the real upstream id instead of falling through to the default. raw_model preserves the original display label for provenance.

Applies to any row surfacing a display label (product/ensemble or
not), matching the dogfood evidence (is_ensemble=false with a model_id).

Test plan

• 5 new recommend()-level tests covering the model_id substitution paths.
• 1 end-to-end CLI test exercising the dogfood scenario.
• GitHub CI runs the full suite on this PR.

Docs

README, recommended-models, and CHANGELOG updated to reflect the new
model_id-aware recommendation behaviour.

References

• Bead: sy-i7a
• Closes --best-model-for should not pass SynthBench display names as provider model IDs #519 (re-opened after Hermes v1.5.4 dogfood)
• Builds on: sy-kh3 (fix(synthbench): refuse display-label model recs from --best-model-for (sy-kh3) #521 — refuse-display-label fallback)
• MR: sy-wisp-7u9
• Polecat: garnet
• Branch: polecat/garnet-mpj27ppb