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>

app/backend/internal/mcpserver/server.go

@@ -147,6 +147,8 @@ func init() {
 	register(spec{"containr_webhooks_deliveries", "List recent delivery attempts for a webhook. Args: id.", "GET", "/webhooks/{id}/deliveries", []string{"id"}, nil, false})
 	register(spec{"containr_webhooks_test", "Queue a test ping delivery for a webhook. Args: id.", "POST", "/webhooks/{id}/test", []string{"id"}, nil, false})
 
+	register(spec{"containr_operations_get", "Cross-cutting operations view: active deployments, deploy queue depth, recent failures, cron runs, backups.", "GET", "/operations", nil, nil, false})
+
 	// Nodes / agent tokens (admin)
 	register(spec{"containr_nodes_list", "List node agents (admin)", "GET", "/agents", nil, nil, false})
 	register(spec{"containr_nodes_get", "Get a node agent (admin)", "GET", "/agents/{id}", []string{"id"}, nil, false})