Update Dockerfile.base to use ghcr.io/shopware/docker-dev as base image

[Soner (shyim)]

Summary

Updates Dockerfile.base to use ghcr.io/shopware/docker-dev:php${PHP_VERSION}-node${NODE_VERSION}-caddy as the base image instead of building from scratch.

Changes

• ✅ Switch to ghcr.io/shopware/docker-dev as base image
• ✅ Make PHP and Node versions configurable via build args (PHP_VERSION, NODE_VERSION)
• ✅ Add bun installation from oven/bun:alpine
• ✅ Make PHP memory_limit configurable via PHP_MEMORY_LIMIT environment variable
• ✅ Switch to root user for package installation, then back to www-data
• ✅ Simplify Dockerfile by leveraging pre-installed packages in base image

Benefits

• Smaller and simpler Dockerfile - No need to install PHP extensions or Node.js from scratch
• Better maintenance - Base image is maintained separately with latest PHP/Node versions
• Configurable - Can build for different PHP versions using build args
• Environment variable support - PHP memory_limit can be configured at runtime

Testing

• ✅ Built and tested locally with PHP_MEMORY_LIMIT=1G
• ✅ Verified PHP 8.3.31 is working
• ✅ Verified Node.js v24.16.0 is working
• ✅ Verified Bun 1.3.14 is working
• ✅ Verified memory_limit is configurable via environment variable

Breaking Changes

None - The image should be backward compatible. The build pipeline will continue to work with the matrix strategy for multiple PHP versions.

[Codecov Comments Bot (codecov-commenter)]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 47.35%. Comparing base (e441e13) to head (15b1555).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1174   +/-   ##
=======================================
  Coverage   47.35%   47.35%           
=======================================
  Files         231      231           
  Lines       16512    16512           
=======================================
  Hits         7819     7819           
  Misses       8693     8693           

Flag	Coverage Δ
go-test	47.35% <ø> (ø)

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