* feat(app): give compact Changes an overview and a straight rail
Three fixes to the Explorer's Changes tab on phones, where there is no
tree rail and the diff is the only view of what changed.
No placeholder stat while the sidebar slides in. `useCheckoutDiffQuery`
reported `isLoading` only when the query was enabled and connected, so an
inactive retained panel settled on `files: []`. The comparison toolbar
summed that into "+0 -0" and the body rendered "No changes" for a diff
nobody had fetched yet, both replaced a moment later by real numbers. The
result now derives from the payload alone: no payload means loading,
whatever the query is doing. Callers already handle loading correctly, so
nothing downstream needed a special case.
Jump to file. A floating action button over the diff opens a sheet with
the same changed-files tree the desktop rail renders; tapping a file
closes the sheet and scrolls the diff there. `ChangedFilesTree` moved out
of `diff-pane.tsx` into its own module so both surfaces own one tree, and
its list is now the sheet-aware one so it scrolls with the sheet gesture
on native. `DiffDocument` takes a `contentInsetBottom` so the button
never traps the last line.
Rails on the compact header. The tab labels sat at 20dp and the close X
at 16dp while every toolbar row below them used 12dp leading and 8dp
trailing. The close button was also a hand-rolled Pressable rather than a
ToolbarButton. `paneContentToolbarTrailingPadding` now takes whether the
row's last control is a bare glyph or a framed one: a glyph's hitbox
overhangs its ink so the row pads by less than the rail, but the compact
git-actions trigger paints its own frame and was landing flush against
the screen edge. The commits header chevron moved to the depth-0 tree
rail. Desktop geometry is unchanged.
* fix(app): preserve Explorer touch targets and reset file overview
* fix(app): preserve diff selections across repaints
Header typography refreshes and height resizes changed the repaint callback
and inadvertently cleared active source selections. Keep selection updates
stable while retaining explicit source and selection-layout invalidation.
* test(app): express diff copy regression as user actions
* test(app): express file overview flows as user actions
