AltGr + Precise KeyMask detection

[exlee]

Hey,

I'm using Alt-1.. for my keybinds and also Alt-Shift-3 for specific screenshot app. That's when I found that Alt+<anything>+<N> is handled by Alt+<N>.

Didn't want to bother with a feature request so I made a pull request instead.

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PR contents

Precise keymap mask handling

So Alt+N handles ONLY Alt+N, non-matching mask combinations are left unmatched and returned to system dispatcher.

AltGr recognition

Since I was already at keys, another long standing issue was inability to use AltGr+N keys (which has some helpful symbols like €, §, •, ° (for 25°C),‹, ›.

So Left Alt/Option is recognized as Alt/Option, Right ALT is recognized as AltGr

Side effect: If someone is using LeftAlt+ and RightAlt+ this patch will make them unhappy.

AI-Assisted Contribution Notice

This contribution was produced with substantial assistance from AI (Codex/GPT 5.5).

My personal contribution:

• Directly defined how cases should be handled
• Reviewed output code and making sure the output is sound and change doesn't expand beyond scope
• Tested (in context of the feature) happy paths and as well as edge cases
• Filled in the paperwork (this PR)

I do not claim authorship because my contribution is too small.
I take full professional responsibility for the quality of the final result.

Please treat this as an offer rather than an expectation. If it isn’t a good fit, feel free to close the pull request.