fix(macos): wake sleeping display at the beginning of capture session

[martona]

Description

Wakes the display at the beginning of the capture session, and does not let it go to sleep while it's active.

macOS does not present any capture frames on a sleeping display, thus the capture thread hangs indefinitely at session start, never sending video data to Moonlight, and therefore is not able to receive any input to wake the display either. The end result is a forever "spinning on connect" Moonlight client, and a hung Sunshine process.

This PR fixes the problem by issuing an IOPMAssertionDeclareUserActivity before capture start to handle the initial wake, and holding an kIOPMAssertPreventUserIdleDisplaySleep assertion for the lifetime of the capture object to prevent sleep.

I realize it's chonky; I could cut this down to about 30-40% of the proposed size by eliminating the display diagnostic logging that I added to help me track down the issue. I think it's useful to have there though, so I'm leaving it in for the original PR; but very much open to reducing it if needed.

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

[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

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