feat(release): publish minimal self-contained Magent source

.dockerignore

@@ -0,0 +1,44 @@
+# Release builds accept only application sources and explicit build inputs.
+# Local configuration, databases, backups, Git metadata and tool caches must
+# never be sent to the builder, even if new directories are added to the repo.
+**
+!Dockerfile
+!.dockerignore
+!LICENSE
+!backend/
+!backend/requirements.txt
+!backend/app/
+!backend/app/**
+!frontend/
+!frontend/package.json
+!frontend/package-lock.json
+!frontend/next-env.d.ts
+!frontend/next.config.js
+!frontend/proxy.ts
+!frontend/tsconfig.json
+!frontend/app/
+!frontend/app/**
+!frontend/public/
+!frontend/public/**
+!docker/
+!docker/supervisord.conf
+!docker/requirements-runtime.txt
+!data/
+!data/branding/
+!data/branding/**
+
+# Defense in depth for accidental private/generated files under allowed paths.
+**/.env
+**/.env.*
+**/__pycache__
+**/*.pyc
+**/*.log
+**/*.db
+**/*.db-*
+**/*.sqlite
+**/*.sqlite3
+**/bootstrap-admin.json
+**/bootstrap-secrets.json
+**/.magent-secrets-*
+**/node_modules
+**/.next