fix: match only required modifiers for popup hotkey

[gmcky]

The Ctrl+C+C popup stops working after the global open hotkey is used once.

Cause: the double-copy detector (setup_global_shortcut) mirrors modifier state
from a global rdev listener into ctrl/shift/alt/meta booleans. That mirror can
desync: when the open hotkey fires, a modifier KeyRelease can be missed, so a
modifier stays flagged as held even though it is physically up. This is a state
bug in the tracker, not a physically stuck key.

The detector then required exact modifier equality with the combo, so a
phantom-held Shift/Alt made a real Ctrl+C no longer match, and the popup went
dead until that modifier was pressed and released again (which resyncs it).

Fix: match only the modifiers the combo requires and ignore extras, so phantom
modifier state can no longer block the combo. This restores the behavior from
before the configurable-hotkey refactor.

Repro (before this change):

1. Use the open hotkey (e.g. Ctrl+Shift+T) once.
2. Select text in another app, press Ctrl+C twice.
3. Popup does not appear. Tapping Shift/Alt makes it work again.

Verify:

• cargo check passes (only pre-existing warnings)
• manual (Windows): open hotkey, then double-copy from an unfocused app, popup appears
• Linux/X11: same behavior confirmed (Wayland global capture is unsupported by rdev)