feat: publish standalone worker

Separate worker packaging and service lifecycle from the control plane.

internal/webapp/page_data.go

@@ -0,0 +1,40 @@
+package webapp
+
+import (
+	"net/http"
+	"time"
+)
+
+// basePageData is the struct every page template receives (embedded
+// into the per-page struct). The shared layout looks up Title,
+// IsLogin, CSRFToken, Version, BuildDate, and StartedAt from here so
+// handlers do not need to repeat those fields on every page.
+type basePageData struct {
+	Title     string
+	IsLogin   bool
+	CSRFToken string
+	Version   string
+	BuildDate string
+	StartedAt time.Time
+}
+
+// newBasePage builds the common fields. isLogin is true for the
+// login page so the layout can hide the navigation; csrfToken is the
+// empty string when isLogin is true (there is no session yet).
+func (s *Server) newBasePage(_ *http.Request, title string, sess *Session) basePageData {
+	return basePageData{
+		Title:     title,
+		IsLogin:   sess == nil,
+		CSRFToken: tokenOrEmpty(sess),
+		Version:   s.deps.Version,
+		BuildDate: s.deps.BuildDate,
+		StartedAt: s.deps.StartedAt,
+	}
+}
+
+func tokenOrEmpty(sess *Session) string {
+	if sess == nil {
+		return ""
+	}
+	return sess.CSRFToken
+}