fix(latency): eliminate scene-change brightness latency with fast-con…

[1Bharat007]

…firm burst engine

Description

Fixes #

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to change)
• 📝 Documentation update
• ♻️ Refactor (no functional changes)
• 🧪 Test improvement

Changes Made

Testing

• cargo fmt — no formatting issues
• cargo clippy -- -D warnings — no warnings
• cargo test — all tests pass
• npm run build — frontend compiles successfully
• Manual UI verification (if applicable)
• Edge cases tested (if applicable)

Screenshots

Checklist

• My code follows the project's coding standards
• I have performed a self-review of my code
• I have added comments to hard-to-understand areas
• I have updated relevant documentation
• My changes do not introduce new warnings
• No unwrap() or expect() in production Rust code paths
• ARIA labels added to any new interactive UI elements