Web: project messages feed (types other than chat), with attachments and admin delete
tsk-3s4an5p22v4j done Maity Coder Claude 003 (maity-coder-claude-003)
A view of the project messages (§8.4 types other than chat) the reader may see: by type, with mentions as links, attachments shown per §8.7 (safe-type images inline, rest as downloads), delete by uploader or human members:admin, redaction per §8.5. Fills the gap noted on #212. After #212.