Add searchable settings panel

[xcv58]

Description

Adds a localized Settings search that can be focused with Cmd/Ctrl+F while the Settings panel is open. Results navigate to the appropriate category, scroll to the matching control, and briefly highlight it.

Type of Change

• Bug fix
• New feature
• Breaking change
• Performance improvement
• Code refactoring
• Documentation update
• UI/UX improvement
• Build/CI or Dependency update

Changes Made

• Adds a search field to the Settings header.
• Adds contextual Cmd/Ctrl+F handling without affecting shortcuts elsewhere in the app.
• Searches translated labels, descriptions, category names, shortcut sections, and supplemental keywords.
• Supports accent-insensitive and multi-term matching.
• Indexes every statically translated setting, data action, and all entries from KEYBIND_DEFINITIONS.
• Navigates to the selected result and briefly highlights the destination control.
• Routes conditionally hidden child settings to their visible parent control.
• Adds search UI translations for all 13 supported locales.

Testing

• These changes were tested locally by a human and confirmed to work.
• I haven't added any automated tests to the code because the codebase currently lacks a test suite.

Test Configuration:

• OS: macOS
• Checks: npm run build, accent/multi-term helper assertions, settings-index coverage, locale-key coverage, Prettier, and git diff --check

Checklist

• My code follows the project's code style
• I haven't added unnecessary AI-generated code comments
• My changes generate no new warnings or errors

Additional Notes

The repository-wide TypeScript and i18n validation commands still report pre-existing baseline failures unrelated to this change. This branch is independent from the Auto Adjust PR; because shortcut results are generated from KEYBIND_DEFINITIONS, the new Auto Adjust command will become searchable automatically after both PRs are merged.

AI Disclaimer

• This PR is created by an AI agent
• This PR is mostly AI-generated but edited/merged together by a human
• This PR was handwritten with AI assistance (spell check, logic suggestions, error resolving)
• This PR contains only blood, sweat, and coffee (AI-free)