Greptile re-review of 6771a0e681:
- A polled MCP screenshot tool re-caches identical pixels under a new
path on every call, so each copy was embedded and re-sent on every later
request, past the per-image cap (3 in delegated children by default).
Each attachment now reserves through `repeat_refusal`, keyed on the
resized data URL (same pixels, same key); a refused image keeps its
MEDIA: path with an "already in context" line.
- Decode/resize ran on the tool thread, so a parallel tool batch of
image-heavy MCP calls could decode many large images at once on a shared
gateway. Prep now runs on the bounded `_vision_cpu_executor`
(auxiliary.vision.max_concurrency), as vision_analyze's encodes do.
3f3df8d4d7