v4.6.4

Fixed

• upload_file base64 now tolerates dirty input instead of failing with kie's opaque atob error (#62). kie's uploader rejects any non-conformant base64 with a confusing doubled "Base64 decoding failed: … atob() … invalid base64-encoded data" message. A new normalizeBase64 step runs before the upload: strips a data:<mime>;base64, prefix, removes whitespace/newlines (encoders wrap at 76 cols; the MCP transport can insert them — the most likely real cause), and maps base64url (-/_) to standard. If the payload is still invalid it returns an actionable client-side error ("length N not a multiple of 4 — likely truncated in transit; re-send or use file_url") instead of passing corrupt data to kie. Verified live: clean and newline-wrapped JPEGs upload; a truncated payload returns the clear error.
• Tool schema note added: very large images can be truncated when passed as a tool argument — prefer file_url with a public URL for those.