Add deployments feature page and deploy trigger on services

[PianoNic]

Summary

• Hand-rolled DeploymentsService (list with optional serviceId filter, logs as plain text, create, cancel)
• Deployments list page with service filter, status color hint, truncated digest, cancel button disabled for terminal states
• Deployment detail page that polls /logs + deployment every 2s, parses JSON log lines, auto-stops on terminal status and ngOnDestroy
• "Deploy now" per-service inline form on the services page, navigates to /deployments?serviceId=... after create
• Dashboard nav card and cross-page nav links added
• Two new lazy auth-guarded routes: /deployments and /deployments/:id

Closes #27