feat: Enhance contract ABI binding generator (#336)

[cyber-excel10]

Closes #336

feat: Enhance contract ABI binding generator with type-safe interfaces and event support (#336)

What i changed?

Updated the contract binding generator so it actually emits fully type-safe interfaces across all supported client languages, along with complete event type definitions extracted directly from contract metadata.

Before this, a lot of parameter types were falling back to overly generic traits like impl ToString, which made client-side integration error-prone and clunky. Complex types (nested Options, Results, Vectors, Maps) are now serialized properly without manual casting hacks on the caller side.

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Key Changes

• Event type generation: Reads contract metadata at codegen time and emits corresponding typed event structs/interfaces for each language.
• Strict type annotations: Replaced loose string-coercion parameter bindings with real concrete types.
• Complex type serialization: Cleaned up encoding/decoding logic for Option<T>, Result<T, E>, Vec<T>, and HashMap<K, V>.
• Multi-language generator updates: Refactored the core codegen drivers for Rust, TypeScript, Python, and Go.
• Test suite: Added bindings_tests.rs covering edge-case types, malformed metadata handling, and multi-language snapshot comparisons.

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Feature Overview

• Full type safety across Rust, TypeScript, Python, and Go
• Automatic event payload definitions from ABI metadata
• Proper nested/complex type serialization
• Extensive end-to-end unit and snapshot test coverage
• 100% Backward Compatible — existing CLI flags and generated code entrypoints remain unchanged

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How it was tested

• Created bindings_tests.rs to exercise the ABI parsing pipeline against real .wasm binaries.
• Verified generated output builds and compiles cleanly across all four target environments:
  • Rust (cargo check passes on output client.rs)
  • TypeScript (tsc --noEmit clean on client.ts)
  • Python (mypy static verification on client.py)
  • Go (go build check on client.go)
• Handled invalid WASM input gracefully with proper error messages instead of standard panics.

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Usage Examples

Generate bindings using the standard CLI workflow:

# Rust
starforge contract generate-bindings ./contract.wasm --lang rust > client.rs

# TypeScript
starforge contract generate-bindings ./contract.wasm --lang ts > client.ts

# Python
starforge contract generate-bindings ./contract.wasm --lang python > client.py

# Go
starforge contract generate-bindings ./contract.wasm --lang go > client.go

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