eval(sync): add reproducible 26-task runner

[wpyaoxueros]

Summary

• Adds the synchronous 26-task rollout runner used for the completed 520-episode evaluation.
• Uses external, per-task VLM and VLA asset interfaces rather than private filesystem paths.
• Locks official stage scoring to d9f83ac5182e25ad7f0a301a77a0b667f2392df1; missing scorer assets fail fast.

Validation

• 110 passed under tests/sync_eval_26.
• 26-profile preflight passed against the locked local asset map.
• Public-path audit passed: no user-specific filesystem paths or account names in the sync runner/tests.

Remaining before review

This PR stays draft until the published Hugging Face weight repository has completed upload and all profiles are updated to its immutable revision.