feat(ops): /operations endpoint + page — live jobs, queue depth, failures

GET /api/v1/operations aggregates active deployments, per-service
deploy-queue depth via Queue.Snapshot(), 24h deployment failures,
cron runs and backups scoped to the caller's projects (admins see all).

Frontend /operations page (Operate nav) shows in-flight count, queued
depth, failures and backup stats with live refetch while deploys are
active. CLI `containr operations` + MCP containr_operations_get.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

docs/guides/CLI.md

@@ -82,6 +82,8 @@ webhooks list|create|update|delete|deliveries|test
                                outbound signed webhooks — create <name> <url>
                                --event 'service.*' (repeatable, '*' = all);
                                deliveries are HMAC-signed (X-Containr-Signature)
+operations                       live ops view: active deploys, queue depth,
+                               24h failures, cron runs, backups
 up                               deploy the current directory
 ```