openai/gpt-chat-latest → A (4:1)

Side A delivers cohesive, lasting parser and rendering improvements: it introduces typed deterministic block masking, a prose item-reference tokenizer that correctly avoids code fences and trims URL punctuation, enforces braced DSL bodies, updates linkification for raw URLs/external references, and adds extensive tests covering these behaviors. Side B is a very large architectural refactor that replaces many REST endpoints with a new RPC layer and renames thread/room concepts, but much of the patch is migration and code movement rather than clearly new functionality, making its enduring value less certain than A's targeted correctness improvements.