More efficient Markdown for Agents conversion

Markdown for Agents now converts HTML with an in-process streaming engine at the edge. It processes content as it arrives instead of buffering the HTML response and sending it to a separate conversion service. This reduces conversion overhead and memory use.

This release also changes the conversion limit and response headers:

• Conversion supports up to 6 MiB (6,291,456 bytes) of decompressed HTML, increased from 2 MiB (2,097,152 bytes). The limit applies after decompression, not to the compressed response size.
• Converted responses no longer generate the x-markdown-tokens or x-original-tokens headers. Clients that use these values need to calculate token counts themselves.
• Content-Length is removed from converted responses rather than recalculated, because the Markdown body is streamed.

For more information, refer to the Markdown for Agents documentation.