f5ac77634b
This PR optimizes memory usage in the APIPlaintextFrameHelper by replacing the vector-based header buffer with a fixed-size buffer, similar to what's already done in the noise protocol implementation. - Replaced `std::vector<uint8_t> rx_header_buf_` with a 5-byte fixed buffer `uint8_t rx_header_buf_[5]` - Implemented a modified protocol parsing algorithm that validates the indicator byte without storing it - Ensured compatibility with noise protocol by supporting message sizes up to at least 65535 (requires 3-byte varint) - Improved readability with clearer conditional logic and better comments - Added detailed notes about protocol limitations and variable length encoding - Reduces memory fragmentation by eliminating dynamic allocations during header parsing
