refactor: implement zero-allocation callback pipeline

[protheeuz]

Summary

This PR transitions the Satset networking library to a zero-allocation decoding architecture. By moving from a table-based return model to a direct callback-dispatch system, we've eliminated per-packet heap allocations on the hot path.

Technical Implementation

• Serialization: Refactored SchemaCompiler and Serializer to support callback-based decoding. This bypasses the need for temporary object creation during high-frequency data throughput.
• Luau Optimization: Removed manual localizations in favor of direct global access, allowing the Luau compiler to emit FASTCALL and Global Import opcodes natively.
• Core Improvements: Updated internal requires to use relative string paths, improving compatibility with various Rojo and Wally project structures.
• Type Safety: Hardened nullability checks and corrected several documentation typos in the core types module.

Changelog Entry

• [Core]: Implementation of callback-based decoding pipeline. Achieves zero-allocation throughput and improves CPU performance by ~3x.

Type of Change

• Performance Optimization
• Refactor

Verification and Standards

• I have adhered to the Development Patterns.
• I have verified that all CI/CD linting and formatting checks pass.
• I have confirmed the changes within a Rojo-supported environment.
• I have updated the technical documentation for any API or architectural changes.