macOS: validate PolterType on Apple Silicon

[vstrelnikof]

v0.6.2 is the first release validated on real Mac hardware — macOS 15 on Intel (thanks @shohart, #1). The DMG ships a universal binary, so Apple Silicon should work, but nobody has confirmed it end-to-end yet, and we say so honestly in the README.

If you have an M-series Mac, running through this list (in any order, partial reports welcome) would directly unblock wider macOS promotion:

• First launch from the DMG: Gatekeeper right-click → Open path, Accessibility + Input Monitoring prompts appear, tray icon shows up, no Dock icon lingers
• Typing in the wrong layout gets detected and the word corrected (e.g. en-US + a Cyrillic layout, or any pair you actually use)
• Layout switching matches input sources correctly (including the PC/"Win" input-source variants — RussianWin / UkrainianWin / ABC)
• Pause hotkey (Ctrl+Shift+P on macOS) and force-switch hotkey work
• "Start automatically when I sign in" registers a LaunchAgent and survives a reboot; unticking removes it
• The self-updater: this is the riskiest one — the .app-bundle swap has never run on real hardware. When the next release lands, does "⟳ Restart to update" actually swap the bundle?

Report with the bug template (it asks for the About-pane version and a log excerpt — release builds never log typed text, so logs are safe to paste).

[vstrelnikof]

Bumping this deliberately: PR #17 makes it more important, not less.

That PR changes the macOS input backend in two ways that only a Mac can
falsify:

• the event tap now subscribes to FlagsChanged (macOS: decide the fate of the modifier-keycode arms — the tap mask never delivers FlagsChanged #4), so modifier presses
  reach the engine's word buffer for the first time — a wrong mapping there
  ends a word silently rather than erroring;
• the emitter clears event flags and posts modifier releases (macOS: implement KeyEmitter::release_modifiers (chord-accepted suggestions can misfire) #5), which is
  the difference between a correction typing text and a correction firing
  ⌘⌫ at your document.

It also adds a Setup pane (#10) whose macOS half calls AXIsProcessTrusted,
IOHIDCheckAccess and the x-apple.systempreferences: deep links. All of it
compiles in CI. None of it has ever executed.

So the checklist above is unchanged and now has three more lines' worth of
reason to exist. If you have an M-series Mac, the two highest-value items are
still the ones nobody has done:

• typing with modifiers held — does a word survive Shift, Caps Lock, Fn+arrow?
• accepting a suggestion with Ctrl+Shift+<digit> while still holding the chord
• the updater's .app-bundle swap, which remains the riskiest untested path

Partial reports are genuinely useful — "Fn+Left ate my word" is a complete bug
report for the first line.