[Backend Release] v0.50.0

[deploystack-automation]

Backend Release v0.50.0

This PR prepares a new backend release.

When merged, this will:

1. Create a release tag
2. Build and publish a multi-architecture Docker image to Docker Hub

The Docker image will be available at:

• deploystack/backend:latest
• deploystack/backend:v0.50.0

Supported Architectures

• linux/amd64 (Intel/AMD)
• linux/arm64 (Apple Silicon, AWS Graviton)

Release notes:

• feat(backend): add email notifications for MCP installation events (448e6871)
• feat(all): queue MCP server deletion as background job with cascade notifications (679fcb53)
• fix(backend): notify satellites when auto-installing MCP servers for new teams (b3df7171)
• feat(all): add user configuration support in installation process (cd26a0ec)
• docs(all): update feature list with per-tool access controls and catalog improvements (d4ec4926)

[deploystack-automation]

Release Branch Cleanup ✅

Branch backend-release has been automatically deleted after PR was merged.