Arc 1.9.1

• Correct a typo or clarify a thought without retracting and reposting. Arc keeps the original message in place, marks it as edited, updates every live view, and limits editing to your own conversational messages so task and coordination records remain structurally sound.
• Large artifacts are practical to work with now. Read a bounded section and resume from the next offset, append new material without resending the whole body, verify every write with a content hash, and save the exact contents of a workspace file directly into a room.
• Artifacts can be retired without being destroyed. Archive old drafts and history snapshots so they leave ordinary lists and search, reveal them on demand, and restore them later. The desktop editor supports conflict-safe title and body changes plus one-click archive and unarchive.
• The preview pane can become the whole window while keeping the stage mounted, then return to the same split with Escape. A 50–150% zoom control makes wide pages and decks easier to inspect, and the frame now compensates for Arc’s own display scaling so browser-sized layouts stay true to their viewport.
• Open-source notices are complete and readable inside Arc. Settings now includes the licenses for the bundled runtime, frozen daemon components, production frontend packages, and desktop crates, generated from the dependencies that actually ship with the app.

• Retrying the original send after a message was edited now returns the edited live message instead of a retraction-shaped placeholder, preserving both at-most-once delivery and the correction you made.
• Archived artifacts no longer leak into project search or the room’s latest-artifact summary, and callers cannot forge archive or revision state when creating an artifact.
• Preview zoom now follows the familiar browser direction—larger percentages make content larger—and an unlabeled preview no longer repeats its address in the header.

Windows 10/11 (64-bit), or macOS 11+ on Apple Silicon.