release: v2.7.2
Merged
AN
4h ago+20+20+01234567890123456789-11-11-01234567890123456789
Version bump, changelog heading and release notes for 2.7.2.
Summary by cubic
Prepares the 2.7.2 release: bumps all package versions to 2.7.2, updates bun.lock, and moves the changelog out of "Unreleased" with release notes.
The release fixes two bugs: keep-warm sessions saved by 2.6 or earlier are no longer dropped on the first 2.7 start (addressing #677), and server-fallback boundaries are restored even after a context manager clears their thinking text.