Adds a share action to the Instant View photo viewer that downloads the
media and re-sends it from the user's own account with a text_url caption
linking back to the source article.
- src/main.py: hooks PhotoViewer.onPhotoShow, injects the toolbar item
- src/ivmedia.py: resolves the viewer's page block to a TL media object
- src/picker.py: share sheet + comment field (restores focus after the
keyboard animation, which PhotoViewer.showShareAlert does itself)
- src/sender.py: FileLoader download, cache reuse, re-send with caption
- src/icons.py: IconManager-aware drawable lookup so icon packs apply
- tools/verify_bundle.py: offline checks for URL acceptance, caption
entity shape and bundled-module isolation
Drops the sample greeting/textutil modules.