Breaking changes

• cog run is now cog exec. cog run still works as a hidden alias with a deprecation warning -- existing scripts won't break yet, but update them. (#2916)

Bug fixes

• async def setup() actually runs now. In 0.17.x, async setup coroutines were silently dropped -- setup appeared to succeed but none of the code executed, causing AttributeError on every prediction. (#2921)
• Async setup shares the event loop with predict. Models that create event-loop-bound resources in setup() (httpx clients, aiohttp sessions, asyncio queues) no longer crash because setup and predict run on different loops. (#2927)
• dict and list[dict] work as input types. These were supported as outputs but rejected as inputs, breaking chat-style message inputs. (#2928)
• list[X] | None works as an input type. The type system only had Required, Optional, and Repeated -- not optional-and-repeated. Both the Python SDK and Go schema generator now handle this correctly. (#2882)
• Unknown prediction inputs are dropped instead of rejected. Coglet was returning 422 for unrecognized input fields, breaking backwards compatibility when models upgraded to new Cog. Unknown fields are now silently stripped and logged at warn level. (#2943)
• Metrics bugs in coglet. Fixed precision loss for large integer increments, empty/malformed metric key panics, missing metrics in error/cancel responses, and inconsistent metrics in state snapshots. (#2896)

Improvements

• Push progress during image export. cog push now shows status during the docker save phase instead of sitting silent while large images export to disk. (#2797)
• Metric name validation. record_metric() enforces naming rules -- must start with a letter, no consecutive underscores, max 128 chars, max 4 segments. predict_time and the cog. prefix are reserved. (#2911)