docs: connect Pages API references to practical guides

[LauraGPT]

Summary

• Connect English and Chinese API reference welcome pages to localized native Transformers quickstart and Python SDK guides.
• Restore only the retained Chinese API page from gh-pages during publication. Preserve its existing entries and numeric deep links instead of overwriting it with the differently numbered current English reference.
• Validate both API inputs before modifying the outgoing publication directory; replace the guide entry idempotently.

Verification

• 81 related tests passed, with two unrelated legacy browser tests deselected. New regression tests first failed on the missing behavior.
• Compared complete generated English and pinned published Chinese API DOMs before/after: unchanged except for the new guide entry. Byte identity is not claimed after HTML serialization.
• Six actual Chromium cases: EN/ZH at 320, 390 and 1440px, no document overflow, links open the correct-language live SDK guide and its tested alignment helper. Representative screenshots inspected.
• The initial browser network-idle check timed out on the old Chinese page's external font dependency; final checks use document readiness and actual navigation. No claim that every external font loaded.

This does not update the historical Chinese API's extracted signatures, add native timestamps/diarization, change model weights, or release a Python package. The published guide destinations carry the maintained toolkit/native capability boundaries.