BridgeJS: expand integer and raw-value enum support

[kateinoigakukun]

Summary

• add BridgeJS support for fixed-width integer types across code generation, link-time JS glue, and runtime intrinsics
• simplify raw-value enum modeling by reusing BridgeIntegerType instead of maintaining a separate integer-width mapping
• complete the missing optional and 64-bit raw-value enum paths, including correct bigint handling for JavaScript glue
• expand snapshot, runtime, optional, and array coverage for fixed-width integers and raw-value enums, then regenerate checked-in BridgeJS outputs

Testing

• mise exec -- ./Utilities/format.swift
• mise exec -- swift test --package-path ./Plugins/BridgeJS --filter BridgeJSCodegenTests
• mise exec -- swift test --package-path ./Plugins/BridgeJS --filter BridgeJSLinkTests
• mise exec -- ./Utilities/bridge-js-generate.sh
• mise exec -- make unittest

[krodak]

This is great 👏🏻 🙌🏻