[Backend Release] v0.53.0

[deploystack-automation]

Backend Release v0.53.0

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:v0.53.0

Supported Architectures

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

Release notes:

• fix(backend): correct satellite command event types for MCP deletion operations (0ca6146a)
• feat(all): add satellite selection to MCP client configuration (34d1a797)
• fix(backend): properly delete MCP installations and notify satellites during team deletion (6d82fb35)
• fix(backend): preserve satellite commands during account deletion (6db38fa0)
• feat(all): add satellite_url field with auto-detection and first-heartbeat updates (6ec441c8)
• feat(all): add self-service account deletion (9f968f25)
• feat(backend): add satellite_url field to team satellites endpoint (af13d14c)

[deploystack-automation]

Release Branch Cleanup ✅

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