Omega v0.2.0-rc21

Omega v0.2.0-rc21

• Restores window dragging. title_bar::init was only ever called from the collab crate, and retiring collab took the call with it, so no window in any mode had a drag region since 2026-07-25.
• Lets the default mode chat again. Zero base returns early from provider authentication, which left the direct-key fallback unreachable whenever the hosted broker did not complete.
• Draws one sidebar in the default mode instead of two.
• Mirrors a running turn to a paired phone as it happens: deltas leave the host on their own interval rather than riding the five-second heartbeat, tool calls and delegations cross with their state, and thread times come from the desktop's own record.
• Shows a turning indicator on a collapsed delegation card, and keeps the stop control in the expanded card.
• Syncs the fork with thirty-six upstream Zed commits.

SHA-256: 715afaa5aa162ac6c888410d166f157891b496f53585bd42ba3b19cf3291ec81