What's Changed
- test-infra: per-process test port for true parallel-run safety (fixes the local ConnectionRefused cascade) by @nesquena-hermes in #4292
- Release PK (v0.51.450): preserve custom provider namespace prefixes in model normalization (#4278) by @nesquena-hermes in #4294
Full Changelog: v0.51.449...v0.51.450