feat: add wallabag template

[NightVibes33]

/claim #152

Summary

Adds a wallabag Dokploy template as a separate focused PR:

• wallabag 2.6.14 web service exposed on port 80
• MariaDB 11.4 backend with generated root/app database passwords
• Redis cache service with persistent storage
• persistent image uploads volume
• domain, server name, and sender email wiring through template.toml
• metadata and SVG icon entry in meta.json

Review notes

• kept separate from feat: add 11 Dokploy templates #883 so the larger template PR stays focused and this one can be reviewed independently
• follows the official wallabag Docker MariaDB + Redis example while adapting it to Dokploy conventions: no container_name, no explicit networks, and no host port mappings
• official reference: https://github.com/wallabag/docker#docker-compose

Verification

• GitHub Actions validate-docker-compose: passing
• GitHub Actions validate: passing
• GitHub Actions build-preview: passing
• GitHub Actions validate-meta: passing
• node dedupe-and-sort-meta.js
• local TOML/YAML structural validation for this template: compose parses, configured domain service exists, domain port is valid, meta.json entry exists, and the template does not use container_name, explicit networks, or host port mappings
• git diff --check

[github-actions]

built with Refined Cloudflare Pages Action

⚡ Cloudflare Pages Deployment

Name	Status	Preview	Last Commit
templates	✅ Ready (View Log)	Visit Preview	455e191