Post-merge follow-ups for #2740#2735#2734#2690#2676#2738#2684#2689#2733#2739#2462#2687#2736#2618#2697, plus three regressions
found while reviewing them:
- ctrl/cmd+digit while typing no longer switches session tabs (#2503 was
still open in practice: the guard only covered the mod+alt surface binding)
- Shiki template-call sanitizer now covers every bundled grammar, including
the js/ts aliases and embedding grammars; timed-out highlight requests are
memoized and no longer cancel unrelated in-flight requests
- settings flush on suspend uses keepalive and also fires on Capacitor
appStateChange; keeps the selected model persisted across mode switches
- remote-only branches fetch before checkout; range helpers fail clearly
- git status invalidation now fires for runtime adapters too
- settings number inputs and select triggers size in ch so they scale with
the interface font
- recent-activity timestamps tick from one list-level ticker
- Markdown preview find goes through the shared find_in_file keybind with
containment, no longer counts its own bar, and debounces observer runs
- #2676 reverted; #2524 fixed by fading the sticky header's own background
instead of overlaying the content below it
- sticky group headers in the model picker and sidebar render again
(oc-sticky-fade-scroller class restored after 9b9d7069c)
- project switcher names are left-aligned again (wrapper lost in 26dbc2f30)
- tool card quick-open icon is always visible and opens the same line as the
expanded card's button
- tautological tests replaced or removed; new oxlint findings fixed