* fix: pin postgres image to bookworm in docker_example to prevent collation mismatch
The postgres:16 tag silently moved its base from Debian Bookworm
(glibc 2.36) to Trixie (glibc 2.41), causing a recurring collation
version mismatch warning on existing langflow-postgres volumes.
Pin to postgres:16-bookworm in both docker-compose files and update
the README so existing data volumes keep matching the OS locale data.
Refs: https://github.com/langflow-ai/langflow/issues/9608
* docs: pin postgres image to bookworm in current docs compose snippets
Mirror the docker_example pin in the four current docs that publish
copyable Compose snippets pairing postgres:16 with a persistent
langflow-postgres volume. Prevents the same Bookworm-to-Trixie
collation version mismatch warning when users follow docs instead
of docker_example.
Versioned historical docs are left as-is.
Refs: https://github.com/langflow-ai/langflow/issues/9608
* fix: switch postgres pin from bookworm to trixie for OS consistency
Aligns the pinned postgres base with the langflow runtime image, which
moved to Debian Trixie in #12990. Keeping postgres on bookworm would
have diverged the stack and locked the database to an aging glibc that
will receive fewer security backports as bookworm ages into oldstable.
The pin itself still solves the original bug — postgres:16 cannot
silently roll its OS underneath an existing volume.
Document the one-time REFRESH COLLATION VERSION step for users
upgrading from a bookworm-initialized volume in docker_example/README.md.
Refs: https://github.com/langflow-ai/langflow/issues/9608
(cherry picked from commit 7504eb4c72)
