Real-device failure: multiServerUpload uploads to one server then has the OTHERS
fetch it server-to-server via PUT /mirror — those /mirror requests fail from a
browser (net::ERR_FAILED / CORS), so the whole upload returned no blob URL
("Blossom upload did not return a usable blob URL").
Switch blossomService.uploadFile to upload DIRECTLY to each server (BUD-02
PUT /upload) in parallel via uploadBlob, resilient: first success wins, per-server
failures are collected, and if ALL fail the error names each server + the likely
cause (CORS / size / payment) and suggests blossom.band. A fresh signed upload
auth (BUD-11) is created per request.
Tests: blossom-service 11/11 (added partial-failure fallback + all-fail error).
Lint + build clean. Local only.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
