feat(app): add refresh button to review pane - #55021

Adds a Refresh button to the review pane toolbar, after the previous and next file buttons. It uses the browser pane's reload glyph, and shows the shared Loader while it is busy.

Before	After	Refreshing

flowchart LR
  click[Refresh click] --> refresh["review.refresh()"]
  refresh -->|no debounce| inv["invalidate vcs + turn + details queries"]
  inv --> spin["Loader + aria-busy"]
  inv -->|settled| done[reload icon]
  fs[filesystem.changed / idle / side open] --> soon["refreshSoon() (100ms debounce, unchanged)"]

• SessionReviewV2 takes optional onRefresh, refreshing, and refreshDisabled props. Without onRefresh, the toolbar is unchanged.
• The button matches the prev/next buttons 1:1:
  • Same IconButton ghost/small, the same session-review-v2-file-nav-button box (36×28), and no gap.
  • New rotate-clockwise icon: the outline-rotate-clockwise glyph redrawn on the 20-unit grid, like arrow-left and outline-arrow-left. At 16px it draws a 0.8px stroke with a square cap and a miter join, centered, the same as the arrows.
  • The spinner inherits the button's icon color, as it does in the browser pane.
• The review model exposes refresh(), refreshing(), and canRefresh():
  • refresh() invalidates all three diff queries (Git/branch, last turn, session details) at once, without the debounce.
  • The spinner state is keyed by session, so it does not follow you to another session.
  • A click while the button spins joins the refresh that is already running.
  • The button is disabled while the diff query cannot run, for example before the session's stored mode loads or while the server is disconnected.
• The old debounced refresh is renamed refreshSoon. Its behavior does not change.
• New ui.sessionReviewV2.refresh key (English only).
• New review.spec.ts case: change the mocked diff with no filesystem event, click Refresh, check aria-busy while the request is held, then check that the new file shows.