refactor: consolidate Device folder feature

[jderochervlk]

Stack context

Part 11 of the Option 5 folder-feature stack.

• Previous: refactor: consolidate File folder feature #320
• Next: another dependency-clean domain folder

Review this PR as the incremental diff against #320.

Summary

• add the target src/device folder on the unqualified internal Device feature
• merge Gamepad haptics, Geolocation, Web Locks, Screen Wake Lock, and Web MIDI into that complete folder
• replace five qualified source features with the supported WebAPI.Device bundle
• define WebAPI.Device -> WebAPI.Event + Device
• preserve all existing flat public interface modules

Temporary state

• this PR introduces no exclusions, compatibility aliases, or module slices; the Device folder membership and public implication are final
• the domain-specific *Types helpers remain private inside the correct folder pending final cleanup

Review focus

• the coarse Device bundle membership
• removal of the five former consumer-facing feature names
• preservation of public module paths and binding signatures

Verification

• node_modules/.bin/rescript clean
• node_modules/.bin/rescript build --prod --features DOM,Event,Device
• npm run build
• npm test
• npm run format:check
• git diff --check