feat(site): add webpush notification serviceworker (#17123)

* Improves tests for webpush notifications
* Sets subscriber correctly in web push payload (without this,
notifications do not work in Safari)
* NOTE: for now, I'm using the Coder Access URL. Some push messaging
service don't like it when you use a non-HTTPS URL, so dropping a warn
log about this.
* Adds a service worker and context for push notifications
* Adds a button beside "Inbox" to enable / disable push notifications

Notes:
* ✅ Tested in in Firefox and Safari, and Chrome.

cli/server.go

@@ -95,6 +95,7 @@ import (
 	"github.com/coder/coder/v2/coderd/tracing"
 	"github.com/coder/coder/v2/coderd/unhanger"
 	"github.com/coder/coder/v2/coderd/updatecheck"
+	"github.com/coder/coder/v2/coderd/util/ptr"
 	"github.com/coder/coder/v2/coderd/util/slice"
 	stringutil "github.com/coder/coder/v2/coderd/util/strings"
 	"github.com/coder/coder/v2/coderd/workspaceapps/appurl"
@@ -779,7 +780,10 @@ func (r *RootCmd) Server(newAPI func(context.Context, *coderd.Options) (*coderd.
 			// Manage push notifications.
 			experiments := coderd.ReadExperiments(options.Logger, options.DeploymentValues.Experiments.Value())
 			if experiments.Enabled(codersdk.ExperimentWebPush) {
-				webpusher, err := webpush.New(ctx, &options.Logger, options.Database)
+				if !strings.HasPrefix(options.AccessURL.String(), "https://") {
+					options.Logger.Warn(ctx, "access URL is not HTTPS, so web push notifications may not work on some browsers", slog.F("access_url", options.AccessURL.String()))
+				}
+				webpusher, err := webpush.New(ctx, ptr.Ref(options.Logger.Named("webpush")), options.Database, options.AccessURL.String())
 				if err != nil {
 					options.Logger.Error(ctx, "failed to create web push dispatcher", slog.Error(err))
 					options.Logger.Warn(ctx, "web push notifications will not work until the VAPID keys are regenerated")