fix(macos): preserve modifier state in input events

[martona]

Description

Fix macOS keyboard event handling so modifier state is preserved reliably across keyboard and mouse input.

macOS input handling was reusing a mutable CGEventRef for keyboard events. That could leave stale event state behind and caused modifier combinations such as Shift+Enter or Cmd+Tab to be replayed inconsistently.

This change creates fresh keyboard events for each input update:

• Modifier keys use a fresh generic CGEventCreate(...) event with kCGEventFlagsChanged.
• Non-modifier keys use CGEventCreateKeyboardEvent(...) for key up/down events.
• The tracked modifier flags are applied to all keyboard events before posting.
• Mouse events also receive the tracked modifier flags so combinations such as Shift+Click are preserved.

Tested manually on macOS via Moonlight/Sunshine input replay:

• Releasing Shift no longer emits an extra key that was pressed before it; previously, it was prone to do that on occasion.
• Cmd+Tab app cycling works; previously Tab key-up could be lost while Cmd was held.
• Shift+Click preserves modifier state; previously modifier keys did not work with mouse clicks.

Screenshot

Issues Fixed or Closed

Roadmap Issues

Type of Change

• feat: New feature (non-breaking change which adds functionality)
• fix: Bug fix (non-breaking change which fixes an issue)
• docs: Documentation only changes
• style: Changes that do not affect the meaning of the code (white-space, formatting, missing semicolons, etc.)
• refactor: Code change that neither fixes a bug nor adds a feature
• perf: Code change that improves performance
• test: Adding missing tests or correcting existing tests
• build: Changes that affect the build system or external dependencies
• ci: Changes to CI configuration files and scripts
• chore: Other changes that don't modify src or test files
• revert: Reverts a previous commit
• BREAKING CHANGE: Introduces a breaking change (can be combined with any type above)

Checklist

• Code follows the style guidelines of this project
• Code has been self-reviewed
• Code has been commented, particularly in hard-to-understand areas
• Code docstring/documentation-blocks for new or existing methods/components have been added or updated
• Unit tests have been added or updated for any new or modified functionality

AI Usage

• None: No AI tools were used in creating this PR
• Light: AI provided minor assistance (formatting, simple suggestions)
• Moderate: AI helped with code generation or debugging specific parts
• Heavy: AI generated most or all of the code changes

[codecov]

Bundle Report

Bundle size has no change ✅

[ReenigneArcher]

@martona thank you for the PR!

Could you correct the lint error?

[martona]

Yup, for sure. I thought I would wait for all checks to complete before pushing changes. Already done on #5107 though.

[martona]

Done!

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

❌ Patch coverage is 25.00000% with 9 lines in your changes missing coverage. Please review.
✅ Project coverage is 17.83%. Comparing base (f9d1aca) to head (9feeff8).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/platform/macos/input.cpp	25.00%	9 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5102      +/-   ##
==========================================
- Coverage   17.86%   17.83%   -0.04%     
==========================================
  Files         111      111              
  Lines       24005    24009       +4     
  Branches    10619    10620       +1     
==========================================
- Hits         4289     4281       -8     
- Misses      14579    15502     +923     
+ Partials     5137     4226     -911     

Flag	Coverage Δ
Archlinux	11.23% <ø> (ø)
FreeBSD-14.3-aarch64	?
FreeBSD-14.3-amd64	13.37% <ø> (+<0.01%)	⬆️
Homebrew-ubuntu-22.04	13.58% <ø> (ø)
Linux-AppImage	12.16% <ø> (ø)
Windows-AMD64	14.84% <ø> (ø)
Windows-ARM64	13.24% <ø> (ø)
macOS-arm64	19.01% <25.00%> (-0.02%)	⬇️
macOS-x86_64	18.37% <9.09%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/platform/macos/input.cpp	36.76% <25.00%> (-1.24%)	⬇️

... and 40 files with indirect coverage changes

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