v0.7 – Thread-Safe Union-Find Parity + Neural-Guided Weight Interface

This release introduces a major architectural upgrade to the Surface Code decoding framework.

New Features

• Thread-safe Union-Find decoder
• Eliminated shared mutable state
• Stable under OpenMP multi-threading
• Reentrant decode() implementation
• WeightField abstraction layer
• Pluggable edge-weight interface
• Uniform (baseline) weight mode
• Neural-guided weight mode (deterministic mock implementation)
• CLI support
• --weight_mode=uniform
• --weight_mode=neural

Architectural Impact

This release establishes a shared weight-field interface that will support:

• Neural-guided MWPM (v0.8)
• Log-likelihood reweighting
• Hybrid CV + discrete QEC roadmap

Stability

• Verified under --threads=8
• No decoder_fail_rate
• Regression-tested against v0.6
• Stable up to 5000 trials