* chore: re-trigger CI (workflows did not dispatch on prior head)
* fix(image/video gen): make schema delivery instruction platform-neutral
The image_generate and video_generate tool schema descriptions hardcoded
a gateway-only delivery instruction ('display it with markdown
 and the gateway will deliver it'). That schema
is sent on every platform, so on CLI it directly contradicted the CLI
platform hint ('Do NOT emit MEDIA:/path tags ... state its absolute path
in plain text'), and on messaging platforms it was also wrong about the
mechanism (local file paths are delivered via MEDIA: tags, not markdown
image syntax — markdown ![]() only works for URLs).
The per-platform file-delivery convention is already owned correctly by
the platform hints in prompt_builder.py. The tool schema now just
describes the result shape (URL or absolute path in the image/video field)
and defers 'how to deliver' to the active platform's guidance.
Provider/model injection already works via _build_dynamic_image_schema()
(the 'Active backend: <provider> · model: <model>' line); no change there.
f721d2cda9