[Feature]: Support image/file attachments in Chat view for Remote Orca Server sessions #22320

Problem or use case

Problem
In remote sessions, pasting or dropping images and files into the Chat view is blocked
("Local attachments are not available for remote sessions"). Sharing screenshots with the agent
is a core workflow (UI bugs, error dialogs, designs), so this is a major gap when the desktop
app is used as a thin client for a remote Orca server.

Setup

• Server: orca serve on macOS (Mac mini), Orca 1.4.207
• Client: Orca desktop on macOS (MacBook Air), Orca 1.4.207
• Agent: Claude Code

Proposed solution

Proposal
When an attachment is added on the client, upload it over the existing client–server
connection into a temp/attachments directory in the workspace on the server
(e.g. .orca/attachments/) and pass the server-side path to the agent, as local sessions do.
Optionally enforce a size limit and clean up the files when the session ends.

Alternatives or additional context

No response