phsl / new-api

Summary
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1. Vertex AI JSON key upload
   • Accept multiple `.json` files (drag & drop / click).
   • Parse each `fileInstance`; build valid key array.
   • Malformed files are skipped and collected into **one** toast message.
   • Upload list now仅displays valid files; form state (`vertex_files`) 同步保持.
   • On *Submit* keys are re-parsed to prevent async timing loss.

2. Multi-key mode stability
   • Added `multi_key_mode: "random"` to initial form values.
   • `Form.Select` becomes fully controlled (`value`/`onChange`).
   • Toggling the “multi-key mode” checkbox writes default / removes field, so
     `setValues(inputs)` no longer clears the user’s choice.

3. UX / compatibility tweaks
   • Preserve uploaded files when editing any other field.
   • Use `fileInstance` only – compatible with legacy Semi Upload API.
   • Removed redundant `limit` prop on `Form.Upload`.
   • Aggregated error handling avoids toast spam.

Result
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Channel creation/update now supports:
• Reliable batch import of Vertex AI service-account keys.
• Consistent retention of multi-key strategy (`random` / `polling`).
• Cleaner, user-friendly error feedback.