Add screenshot/image paste to the terminal

[benfrank241]

What & why

Pasting an image (e.g. a macOS screenshot on the clipboard, Cmd+Ctrl+Shift+4 then Cmd+V) into a terminal pane currently does nothing. xterm only handles text paste and silently drops image blobs — and since the shell (Claude Code in particular) runs in a server-side PTY, there's no local clipboard for it to read from either.

How

ui/src/components/TerminalCell.tsx:

• Add a capture-phase paste listener on the terminal container. It runs before xterm's hidden textarea sees the event, so image pastes can be handled and text pastes pass straight through untouched.
• When the clipboard has image items, upload them to the session's cwd via the existing POST /api/fs/upload endpoint, then type the resulting on-disk path into the PTY ({type:'input', data: path}).
• This is the same path-handoff the existing file-drop handler already uses — tools like Claude Code recognize an image path and attach it. The shared logic is factored out of handleDrop into a new uploadBlobsAndType helper.
• A small "Attaching image…" badge provides feedback (drop has a drag overlay; paste has none).

Pasted screenshots are saved as pasted-<timestamp>.png in the session cwd.

Notes

• Frontend-only, one file. No backend or dependency changes; reuses /api/fs/upload + /api/fs/:id/browse.
• Text paste behavior is unchanged (the handler early-returns when there are no image items).
• tsc typecheck and vite build both pass.

Test plan

1. Copy a screenshot to the clipboard.
2. Focus a terminal pane running Claude Code and press Cmd+V.
3. The image uploads (badge shows briefly) and its path is typed into the prompt; Claude Code attaches it as [Image #N].
4. Verify a plain-text paste still pastes text as before.

🤖 Generated with Claude Code