fix: mitigate focus corruption from boundary raise races (#355)

When MoveFocus hits a boundary in a scrolling layout, the engine was
falling back and returning ALL visible tiled windows as raise_windows.
Holding down the focus key floods RaiseManager with sequences, each
raising N windows. The queue backs up, so OS focus confirmations
(WindowFocused) arrive out of order and can interfere with the engine's
current focus state.

- Boundary fallback: only focus the selected window, don't raise every
  visible tiled window. This stops the raise queue from exploding when
  a focus key is held at the edge.

- WindowFocused guard: ignore the event if the window is not present in
  the active workspace/layout. Stale/delayed focus confirmations for
  windows that have left the layout are dropped instead of corrupting
  focused_window.

This mitigates the focus corruption described in #285. Further work may
be needed to fully eliminate races between delayed OS confirmations and
subsequent focus commands.

feat: stack layout

feat: handle unresizeable windows

chore: update branding

feat: properly determine hide corner

Revert "perf: don't wake when no raise seq"

This reverts commit 45d77a2.

fix: display churn after sleep

chore: .

chore: fmt

feat: master/stack layout engine (#249)

* feat

* fix

* fmt

* fixes

* fixes

* Update rift.default.toml

* nits

* fmt