Detect denied Accessibility access on macOS 15+ (fixes #48)

[timokox]

Fixes #48. Probably also explains a chunk of the other "v1.10 stopped working on Tahoe" reports.

Root cause

The macOS-15+ branch of the launch-time Accessibility check casts the result of AXIsProcessTrustedWithOptions() to void and moves on:

if (@available(macOS 15.0, *)) {
    NSDictionary *opts = [NSDictionary dictionaryWithObjectsAndKeys:(id)kCFBooleanFalse, (id)kAXTrustedCheckOptionPrompt, nil];
    (void)AXIsProcessTrustedWithOptions((CFDictionaryRef)opts);   // result discarded
}
else if (!AXIsProcessTrusted()) {
    // critical alert + open Settings + terminate
}

The intent is clearly to register with TCC via the no-prompt variant so the app appears in System Settings without nagging on every launch — but the failure mode after major OS upgrades is bad:

1. Tahoe 26.5 (or another upgrade that resets/re-prompts TCC).
2. User has not yet re-granted (or actively denied) Accessibility for Jiggler.
3. Jiggler launches normally, the menu-bar icon turns green when it thinks it is jiggling, but every CGEventPost is silently dropped because the process is not Accessibility-trusted on modern macOS.
4. The Mac still goes to sleep / runs the screensaver.

That matches the user-visible symptom in #48 ("Jiggler appears to run … Mac still goes to sleep") exactly.

Fix

Unify the trust check: the 15+ branch now captures the boolean result of AXIsProcessTrustedWithOptions() (no-prompt behaviour preserved — we still pass kAXTrustedCheckOptionPrompt = false). Both version branches feed into the same if (!accessibilityTrusted) { … alert … open Settings … terminate; } block.

Wording of the alert is also touched:

• "Security & Privacy" → "System Settings > Privacy & Security" (modern pane name)
• "the mouse cursor" → "the mouse and keyboard" (keyboard events are synthesised in some modes too)

Verification

xcodebuild -configuration Debug build → BUILD SUCCEEDED, no warnings. Smoke-tested on macOS 26.4.1: my DerivedData build path is not Accessibility-trusted, so the new check correctly catches the denial and fires the alert + terminate (unified log shows NSAccessibility Request Received → terminate: ~130 ms later). In production a user sees the alert and is deep-linked into the right Settings pane.

Repro path for testers

After installing this build, once: remove Jiggler from System Settings > Privacy & Security > Accessibility, then launch Jiggler. Should now show the alert and open Settings, instead of silently lying about jiggling.