Skills that produce large/lossless images (e.g. info-graph, where a
rendered JPG is 1-2 MB) currently lose quality in Telegram delivery
because `_IMAGE_EXTS` membership routes the file through
`send_multiple_images` → `sendMediaGroup`, which Telegram's server
re-encodes to JPEG @ 1280px max edge. The original bytes only survive
when the file goes through `send_document`, which the dispatch tables
in three places (`_process_message_background`, `_deliver_media_from_response`,
and the `send_message` tool's telegram path) only reach for files
whose extension is NOT in `_IMAGE_EXTS`.
This commit adds an `[[as_document]]` directive that mirrors the
existing `[[audio_as_voice]]` shape: a skill emits the directive once
in its response, and every image-extension MEDIA: file in that response
is delivered via `send_document` instead of `send_multiple_images` /
`sendPhoto`. The directive is detected at the dispatch sites (which see
the raw response) and the directive string is stripped from the
user-visible cleaned text in `extract_media` so it never leaks.
Granularity is intentionally all-or-nothing per response, matching
[[audio_as_voice]]'s scope. Skills that need fine control can split into
two responses.
Verified the targeted use case: info-graph emits
信息图已生成（...）
[[as_document]]
MEDIA:/tmp/info-graph-x/infographic.jpg
→ Telegram receives `infographic.jpg` via sendDocument, original 1MB
JPEG bytes preserved, no recompression. Forwarding and download
filenames stay clean (`infographic.jpg`).
Tests: +3 cases in TestExtractMedia covering directive strip, isolation
from voice flag, and coexistence with [[audio_as_voice]]. All
113 pre-existing media/extract/send tests pass.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
d34f03c32a