feat(Kanbn): add Kanbn template

[sadiqAlAboudi]

What is this PR about?

New PR of Kanbn

Kanbn is a self-hosted open-source project management alternative to Trello.

What's included

• Kanbn web application
• Kanbn database migration service
• PostgreSQL 15
• Persistent PostgreSQL storage
• Dokploy-managed domain configuration
• Generated PostgreSQL password and Better Auth secret
• Environment configuration for the public application URL and database connection

Checklist

Before submitting this PR, please make sure that:

• I have read the suggestions in the README.md file https://github.com/Dokploy/templates?tab=readme-ov-file#general-requirements-when-creating-a-template
• I have tested the template in my instance, so the maintainers don't spend time trying to figure out what's wrong.
• I have added tests that demonstrate that my correction works or that my new feature works.

Issues related (if applicable)

Close automatically the related issues using the keywords: closes #1076

[github-actions]

built with Refined Cloudflare Pages Action

⚡ Cloudflare Pages Deployment

Name	Status	Preview	Last Commit
templates	✅ Ready (View Log)	Visit Preview	30ec10d

[Siumauricio]

Tested with a real deploy on a Dokploy instance (exact template from this branch merged with current canary). Works out of the box, no changes needed.

Upstream / images

• kanbn/kan: AGPL-3.0, active since 2023 (~5.5k stars, 451 forks), release v0.6.0 (2026-06-29) matches the pinned tag.
• ghcr.io/kanbn/kan:0.6.0 and ghcr.io/kanbn/kan-migrate:0.6.0 manifests pull anonymously (200).
• Compose mirrors upstream's docker-compose.yml (migrate → web with service_completed_successfully, postgres:15, same healthcheck) minus container_name/ports/networks.

Validators: generate-meta.js --check ✅ (519 templates), validate-docker-compose.ts ✅, validate-template.ts ✅. Secrets via ${password:32} (BETTER_AUTH_SECRET needs 32+ chars per .env.example) ✅.

Deploy

• migrate-1: [✓] migrations applied successfully! → Exited (0). postgres-1: healthy. kanbn-1: running, RestartCount 0, Next.js 15.5.9 … Ready in 582ms (image already sets HOSTNAME=0.0.0.0).
• https = true in [[config.domains]] was honored: Dokploy created the domain as https://….
• Via the domain: GET / → 307 /login, /login and /signup → 200 «Login | kan.bn».
• NEXT_PUBLIC_ALLOW_CREDENTIALS=true is picked up at runtime: POST /api/auth/sign-up/email → 200 with user + session token, GET /api/auth/get-session → valid session, GET /boards with that cookie → 200. So a fresh install can create its first account without SMTP.

Optional nits (non-blocking)

• logo.svg is just the text "kan.bn" in #ededed with a non-embedded font (Plus Jakarta Sans) — nearly invisible on light backgrounds and depends on the font being installed. A proper mark from kan.bn would look better in the template gallery.
• SMTP is not wired (magic-link login / invites / password reset need it). Fine as-is since credentials login is enabled; users can add SMTP_* vars themselves.

LGTM.