Windowed mode improvements

[eraycantazeguney]

• fix: overlays no longer misplaced when activating HS via Mission Control
  Activating Hearthstone via Mission Control did not refresh the cached window frame, leaving overlays at stale coordinates. The Hearthstone window frame is now reloaded on activation.

• fix: overlay windows no longer cover macOS Notification Center
  Overlay window level was above system UI, hiding the menu bar, status items, and Notification Center. Lowered to just above the normal window level so system UI renders above them.

• fix: final board window no longer lingers when session refreshes
  When the Battlegrounds Session view rebuilds its rows, a row removed mid-hover does not reliably receive a mouse-exit event, leaving the final-board popup orphaned. The popup is now dismissed before the rows are torn down.

• fix: overlays no longer linger when HS loses focus
  The deactivation handler updated the active flag but did not post a deactivation notification (its counterpart was posted on activation), so hide-on-background overlays only updated through the polling loop, with a delay of up to ~2.5 s. The notification is now posted on deactivation.

• fix: counter tooltip popup no longer lingers on game end
  The end-of-match cleanup omitted the counter tooltip window, so hovering a counter at the moment a match ended left the tooltip on screen. It is now included in the dismissal.

• fix: respect "hide when game in background" for more overlays
  Fourteen visibility checks gated solely on Hearthstone being active, ignoring the user's "hide all when game in background" preference. They now apply the same gate used by the other overlays so the preference is honored consistently.

• feat: toasts dim on hover and dismiss on click
  Non-actionable toasts now fade to 30% opacity on hover (excluded in fullscreen) so the content beneath remains visible. Click now dismisses any toast; previously only toasts with an action.