chore(docker): upgrade to postgresql v18

[tembo]

Description

Upgraded PostgreSQL from version 15 to 18 in Docker Compose and verified configuration compatibility. Updated environment variables and volume paths to match Bitnami PostgreSQL 18 specifications.

Changes Made:

• Updated docker-compose.yml image from bitnami/postgresql:15 to bitnami/postgresql:18
• Migrated environment variables to PostgreSQL 18 format:
  • POSTGRES_USER → removed (defaults to postgres)
  • POSTGRES_PASSWORD → POSTGRESQL_POSTGRES_PASSWORD
  • POSTGRES_DB → POSTGRESQL_DATABASE
• Updated volume mount path from /var/lib/postgresql/data to /bitnami/postgresql
• Updated healthcheck command to use new environment variable format
• Added migration guidance in README.md for users upgrading existing local setups

Screenshots / Recordings

N/A

Type of Change

• Bug fix
• New feature
• Breaking change
• UI/UX update
• Docs update
• Refactor / Cleanup

Related Areas

• Authentication
• Calendar UI
• Data/API
• Docs

Testing

• Manual testing performed
• Cross-browser testing (if UI changes)
• Mobile responsiveness verified (if UI changes)

Checklist

• I've read the CONTRIBUTING guide
• My code works and is understandable and follows the project's style guidelines
• I have performed a self-review of my code
• I have commented my code, particularly in complex areas
• I have updated the documentation
• Any dependent changes are merged and published

Notes

Users with existing PostgreSQL 15 local setups should either run bun run docker:clean to recreate the volume or use PostgreSQL's upgrade tooling before starting the new container.

By submitting, I confirm I understand and stand behind this code. If AI was used, I've reviewed and verified everything myself.

Want tembo to make any changes? Add a review or comment with @tembo and i'll get back to work!

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Summary by cubic

Upgraded Docker Compose database from PostgreSQL 15 to 18 using bitnami/postgresql:18. Updated env vars, volume path to /bitnami/postgresql, and healthcheck; removed the README upgrade note.

^{Written for commit 2d078cf. Summary will update on new commits.}

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Project	Deployment	Actions	Updated (UTC)
analog	Ready	Preview, Comment	Mar 25, 2026 1:13am

[tembo]

Requesting review from @JeanMeijer who has experience with the following files modified in this PR:

• README.md

[cubic-dev-ai]

No issues found across 2 files