Stamp the build version into the binary (closes #253)

internal/handlers/handlers.go

@@ -184,6 +184,7 @@ type UserInfo struct {
 type templateDataWrapper struct {
 	User      *UserInfo
 	CSRFToken string
+	Version   string
 	Data      any
 }
 
@@ -234,9 +235,16 @@ func (s *Handlers) renderTemplate(
 	userInfo := s.getUserInfo(r)
 	csrfToken := middleware.CSRFToken(r)
 
+	// The footer in base.html renders .Version. Every page reaches it
+	// through here, so this is the one place that has to supply it;
+	// left unset, the footer falls back to its literal "dev" and the
+	// UI reports a build that is not the one running.
+	version := s.params.Globals.Version
+
 	if m, ok := data.(map[string]any); ok {
 		m["User"] = userInfo
 		m["CSRFToken"] = csrfToken
+		m["Version"] = version
 		s.executeTemplate(w, tmpl, m)
 
 		return
@@ -245,6 +253,7 @@ func (s *Handlers) renderTemplate(
 	wrapper := templateDataWrapper{
 		User:      userInfo,
 		CSRFToken: csrfToken,
+		Version:   version,
 		Data:      data,
 	}