Replace EOL failure crate with thiserror for error handling

[cango91]

Summary

This PR migrates the error handling from the deprecated failure crate to thiserror, which is the modern standard for error handling in Rust.

Changes

• Cargo.toml: Updated both dependencies and build-dependencies to replace failure = "0.1.6" with thiserror = "2.0.12"
• src/error.rs:
  • Replaced use failure::Fail with use thiserror::Error
  • Updated derive macro from #[derive(Clone, Debug, Fail)] to #[derive(Clone, Debug, Error)]
  • Converted all error attribute syntax from #[fail(display = "...")] to #[error("...")]

Rationale

The failure crate has been officially deprecated and is no longer maintained. The Rust community has standardized on thiserror for error handling, which provides:

• Better compile-time error checking
• More efficient error types
• Active maintenance and support
• Better integration with the modern Rust ecosystem

Impact

• No breaking changes: The public API remains identical
• Performance: Potential minor performance improvements due to more efficient error types
• Maintenance: Ensures continued compatibility with future Rust versions
• Dependencies: Reduces dependency on unmaintained crates

Testing

• All existing tests continue to pass
• Error message formatting remains unchanged
• API compatibility is preserved

This migration ensures the library stays up-to-date with modern Rust best practices and maintains long-term viability.