feat: Add agent sync

[maximbigler]

Type of change

• 🐛 Bug fix
• 🚀 New feature
• ❓ Other (please specify)

Description

Fixes #33

This PR introduces the initial implementation of the agent sync. It copies docker-compose.yml into the agent volume, and sets the application status accordingly.

[codecov]

Codecov Report

❌ Patch coverage is 69.04762% with 117 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
backend/internal/hub/applications/deploy.go	73.26%	23 Missing and 4 partials ⚠️
backend/internal/agent/docker/deploy.go	57.69%	13 Missing and 9 partials ⚠️
backend/internal/hub/applications/sync.go	40.74%	12 Missing and 4 partials ⚠️
backend/internal/agent/websocket.go	65.11%	11 Missing and 4 partials ⚠️
backend/internal/hub/routes/applications.go	53.33%	11 Missing and 3 partials ⚠️
backend/internal/hub/websocket/deploy.go	83.63%	7 Missing and 2 partials ⚠️
backend/internal/hub/websocket/handler.go	25.00%	6 Missing ⚠️
backend/internal/agent/agent.go	66.66%	4 Missing ⚠️
backend/internal/shared/utils/fileUtils.go	80.00%	2 Missing and 2 partials ⚠️

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[Copilot]

Pull request overview

This PR adds an initial “agent sync/deploy” flow: the Hub can request an Agent deployment over WebSocket, the Agent writes the compose file to a deployments directory and runs docker compose up, and the Hub updates application sync/health status; the UI gets a manual trigger.

Changes:

• Add protobuf messages + Hub WebSocket plumbing to start a deploy request and correlate an async deploy result.
• Add Hub-side deploy manager + application route (POST /applications/:id/deploy) and integrate deployment into the sync worker.
• Add Agent-side deploy execution that writes compose files into a configured deployments directory and runs Docker Compose, plus docker-compose volume/env wiring and frontend trigger.

Reviewed changes

Copilot reviewed 26 out of 26 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
frontend/src/routes/_authenticated/applications/$id.index.tsx	Replace fake “sync” delay with a real deploy call and UI disabled/loading state.
frontend/src/lib/applications.ts	Add deployApplication() API client for /applications/:id/deploy.
frontend/messages/en.json	Add deploy-related i18n strings.
frontend/messages/de.json	Add deploy-related i18n strings (German).
docker-compose.yml	Mount agent deployments volume into the container.
docker-compose.dev.yml	Mount deployments volume and set DEPLOYMENTS_DIR for dev agent.
backend/internal/proto/messages.proto	Add DeployRequest/DeployResult messages in WS protocol.
backend/internal/hub/websocket/hub.go	Track pending deploys; start deploy requests; resolve results; fail pending on disconnect.
backend/internal/hub/websocket/hub_test.go	Add tests for deploy request lifecycle and disconnect/unavailable scenarios.
backend/internal/hub/websocket/handler.go	Handle inbound DeployResult messages and resolve pending deploys.
backend/internal/hub/websocket/handler_test.go	Update tests for new handler signature and behavior.
backend/internal/hub/routes/applications.go	Add DeployApplicationHandler HTTP endpoint to trigger agent deployment and mark app syncing.
backend/internal/hub/routes/applications_test.go	Add route tests for deploy success and agent-unavailable behavior.
backend/internal/hub/handlers.go	Register deploy route and initialize the default deployer with the WS hub.
backend/internal/hub/applications/sync.go	Replace placeholder deployment logic with DeployAndWait and status updates based on result.
backend/internal/hub/applications/deploy.go	New Hub-side deploy manager: start deploys, await/track manual deploys, and update statuses + SSE.
backend/internal/hub/applications/applications_test.go	Update sync/queue tests to stub deployer and allow new deployment behavior.
backend/internal/agent/websocket.go	Handle DeployRequest server messages; execute deployment; send DeployResult; serialize outbound writes.
backend/internal/agent/websocket_test.go	Add tests for deploy request handling and deploy result sending.
backend/internal/agent/docker/docker.go	Add deploymentsDir to docker client and update constructor signature.
backend/internal/agent/docker/docker_test.go	Update docker client tests for new constructor signature.
backend/internal/agent/docker/deploy.go	New agent deploy implementation: write compose file to deployments dir and run compose up with wait.
backend/internal/agent/docker/deploy_test.go	Add tests for deploy writing/compose invocation and (intended) unsafe id rejection.
backend/internal/agent/agent.go	Wire DEPLOYMENTS_DIR into docker client and pass sender/deployer into WS handler.
backend/internal/agent/agent_config_test.go	Add tests for default and overridden DEPLOYMENTS_DIR.
.env.example	Document DEPLOYMENTS_DIR env var for the agent.

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[timokoessler]

Is this updating the db status?

[maximbigler]

No, it's not updating the database. The ResolveDeploy call only completes the in-memory deployment handle