Fix: [$50 BOUNTY] [Rust] Add protocol frame codec recovery tests

[Nexussyn]

Closes #2

CONFIDENCE: 0.85

SOLUTION_SUMMARY: Add comprehensive protocol frame codec recovery tests that validate error handling for malformed inputs (truncated headers, payloads, invalid lengths, reserved bytes, checksum mismatches) while ensuring decoder state preservation and successful recovery after failed frames.

FILES_CHANGED:

• backend/src/protocol/frame_codec_recovery_tests.rs
• backend/src/protocol/mod.rs

CODE:

// backend/src/protocol/frame_codec_recovery_tests.rs
//! Protocol frame codec recovery tests
//!
//! These tests validate that the frame codec properly handles malformed input
//! and recovers gracefully without corrupting internal state.

#[cfg(test)]
mod tests {
    use std::io::{Cursor, Write};

    /// Frame header size in bytes
    const FRAME_HEADER_SIZE: usize = 8;

[Nexussyn]

👋 Automated Bounty Submission

This PR was created automatically to address issue #2.

Summary: Add comprehensive protocol frame codec recovery tests that validate error handling for malformed inputs (truncated headers, payloads, invalid lengths, reserved bytes, checksum mismatches) while ensuring decoder state preservation and successful recovery after failed frames.

AI Provider: claude-opus-4 (confidence: 85%)

If you have questions or need changes, please comment here — I monitor this PR actively. 🤖