Removing the Fix 1 ClearAllHeaders/ClearAllQueryParams block from all 8
upload entry points. CkRest.AddHeader already overwrites by header name,
so the clears were unnecessary; they also wipe the internal state
Chilkat's SigV4 signer relies on between requests, which caused AWS to
reject every PUT with HTTP 400 MaxMessageLengthExceeded (max 35240 B).
Per-step ClearAllQueryParams inside multipart kept (followed immediately
by AddQueryParam).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>