fix(keyboard): Japanese mapping

[FoxRefire]

Description

Fix Japanese keyboard mapping

To be fixed, Need to merge all these PRs

• Fix Japanese keyboard mapping moonlight-stream/moonlight-qt#1984
• fix(keyboard): Japanese mapping #5542
• fix(keyboard): Japanese mapping libvirtualhid#101

Issues Fixed or Closed

• Fixes Couldn't input backslash(\), pipe(|) and Muhenkan in Japanese keyboard moonlight-stream/moonlight-qt#1962

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

See our AI usage policy.

• 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

See analysis details on SonarQube Cloud

[ReenigneArcher]

Requesting changes for the linked keyboard fix at the current heads (Sunshine f5f93a1, libvirtualhid 0271b64, Moonlight 3bace8b).

The new KeyboardEvent::stream_flags is never populated by keyboard_event() here. Sunshine only translates SS_KBE_FLAG_NON_NORMALIZED into uses_normalized_key_code; libvirtualhid #101 checks stream_flags & 0x02/0x04 to distinguish Korean Hangul/Hanja, so those branches are unreachable through Sunshine. The required Moonlight PR #1984 also still maps SDL_SCANCODE_LANG1/LANG2 to Japanese Henkan/Muhenkan key codes and does not emit these extra flag bits. Please coordinate the protocol/client mapping, pass the flags into the libvirtualhid event after its API update, and cover the packet-to-backend path. The current pair of PRs does not fix those keys.

Sunshine #5542 itself is currently mergeable, but this integration needs to be resolved before accepting the linked keyboard fix.