Workspace and transcript selections now flow into the composer as lightweight references so users can carry exact snippets into the next prompt without file-only workarounds. The prompt formatter keeps workspace and chat excerpts separate, and the composer avoids sending chat snippets as fake file attachments.
Constraint: Selection references must prepare model context without polluting backend file attachment payloads.
Rejected: Reuse file attachments for chat selections | would leak chat:// pseudo paths into file-oriented payloads.
Confidence: high
Scope-risk: moderate
Directive: Keep chat-selection references prompt-only unless the backend gains a first-class chat context attachment type.
Tested: bun run check:desktop
Tested: bun run verify
Tested: agent-browser UI smoke for workspace, user-message, and assistant-message selections
Not-tested: Strict Chrome extension channel; connection timed out, local browser automation covered the flow.