* feat(ui): show session info in the sidebar hovercard
The sidebar session hovercard now always opens and shows owner, created and updated times, PR chips with CI state and diff stats, plus a branch and changed-files fallback with “No PR yet”. The progress card renders below when present, and the gateway exposes changedFiles on session PR and branch snapshots.
* fix(ui): scope session hovercards to sidebar rows
Keep Markdown session links owned by their dedicated preview hovercard by limiting both lazy registration and runtime activation to sidebar session rows. Add browser coverage that fails when the competing sidebar hovercard steals the link trigger.
* perf(ui): keep session hovercard data out of startup
Reuse the sidebar’s existing session projection from the lazy hovercard runtime instead of publishing a separate startup-loaded registry. This removes the registry lifecycle and its implementation-only tests while keeping the browser ownership regression and restoring the Control UI startup bundle below budget.
Peter Steinberger