20 feature native decorator metadata symbol.metadata

[Evanion]

This PR modernizes NexusDI by introducing native decorator metadata support and simplifying the module API:

• Native Decorator Metadata: Migrates from reflect-metadata to the new ECMAScript/TypeScript standard using Symbol.metadata. NexusDI now works out-of-the-box with TypeScript 5.2+ and no longer requires reflect-metadata as a dependency or import.
• Unified Module API: Merges the services and providers arrays in module definitions into a single providers array, reducing boilerplate and making module configuration more intuitive.
• Polyfill Included: NexusDI provides a built-in polyfill for Symbol.metadata for environments that do not yet support it natively.
• Documentation & Examples: Updates documentation and code examples to reflect these changes and guide users through migration.

Type of Change

• Breaking change (removes reflect-metadata and changes module API)
• New feature (native decorator metadata support)
• Documentation update

Migration Steps

1. Upgrade to TypeScript 5.2+.
2. Remove all imports of reflect-metadata.
3. Update tsconfig.json:
   • Remove emitDecoratorMetadata
   • Ensure experimentalDecorators is enabled
   • (Optional) useDefineForClassFields should be enabled (default in TS 5.2+)
4. Update modules: Merge services and providers into a single providers array.

Checklist

• Code follows style guidelines
• All tests pass locally
• Documentation is updated
• PR description clearly describes the changes

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✨ May the dependencies be with you!