feat(nodes): remote sleep/wake — idle detection + wake-page ingress

Agents report per-container net IO at heartbeat; the sleeper measures
idleness from those counters for remote services, removes replicas via
the agent queue, and repoints the domain route at the backend's new
/internal/wake-page endpoint (replacePath + priority-100 route in the
file provider). First hit serves a reloading page and retriggers the
wake reconcile, which recreates replicas and restores real upstreams.

Manual POST /services/:id/sleep also routes remote; local sleep/wake
flow is unchanged.

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

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

app/backend/internal/database/sqlcdb/querier.go

@@ -139,8 +139,9 @@ type Querier interface {
 	// Agent reports the real host bindings after create — persist them with
 	// the status flip so ingress can route to the assigned port.
 	UpdateContainerPorts(ctx context.Context, arg UpdateContainerPortsParams) error
-	// Agent heartbeat reports real docker state; reconcile inventory for rows
-	// this node owns. Tombstones win — never resurrect a removed replica.
+	// Agent heartbeat reports real docker state + net counters; reconcile
+	// inventory for rows this node owns. Tombstones win — never resurrect a
+	// removed replica. $4 is the cumulative rx+tx byte counter.
 	UpdateContainerStateByName(ctx context.Context, arg UpdateContainerStateByNameParams) error
 	UpdateContainerStatus(ctx context.Context, arg UpdateContainerStatusParams) error
 	UpdateDatabaseServiceNameAndPlanByIDAndUser(ctx context.Context, arg UpdateDatabaseServiceNameAndPlanByIDAndUserParams) error