fix: wait for metrics scrape before restarting after switch deployment

After a successful switch deployment, the listener now waits for Prometheus
to scrape the /metrics endpoint before exiting for restart. This ensures
deployment metrics are captured before the process restarts and resets
in-memory counters. Falls back to a 60 second timeout if no scrape occurs.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cmd/homelab-deploy/main.go

@@ -16,7 +16,7 @@ import (
 	"github.com/urfave/cli/v3"
 )
 
-const version = "0.1.13"
+const version = "0.1.12"
 
 func main() {
 	app := &cli.Command{

flake.lock

@@ -2,11 +2,11 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1770562336,
+        "lastModified": 1770197578,
-        "narHash": "sha256-ub1gpAONMFsT/GU2hV6ZWJjur8rJ6kKxdm9IlCT0j84=",
+        "narHash": "sha256-AYqlWrX09+HvGs8zM6ebZ1pwUqjkfpnv8mewYwAo+iM=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "d6c71932130818840fc8fe9509cf50be8c64634f",
+        "rev": "00c21e4c93d963c50d4c0c89bfa84ed6e0694df2",
         "type": "github"
       },
       "original": {

internal/metrics/server.go

@@ -36,7 +36,7 @@ func NewServer(cfg ServerConfig) *Server {
 	registry := prometheus.NewRegistry()
 	collector := NewCollector(registry)
 
-	scrapeCh := make(chan struct{})
+	scrapeCh := make(chan struct{}, 1)
 
 	metricsHandler := promhttp.HandlerFor(registry, promhttp.HandlerOpts{
 		Registry: registry,