Salvage of the surviving piece of #2696 by @tarunravi. The PR's other two
changes (tool progress streaming, SSE None-sentinel fix) were independently
superseded on main by the structured hermes.tool.progress SSE events and the
rewritten queue-drain loop.
Remote OpenAI-compatible frontends can't read server-local file paths, so
MEDIA:<path> tags (browser screenshots, generated images) were dead text.
_resolve_media_to_data_urls() now inlines small (<=5MB) local images as
markdown data URLs across all four response surfaces: chat completions
(non-streaming), session chat, session chat stream final event, and the
Responses API. Non-image, missing, or oversized paths pass through
untouched.
2068754d6f