release: 0.4.0: Domain-admin groundwork, send-log auth, packaging fixes

The project's mark is now in use rather than only on file. The README opens
Added:
  - The project's mark is now in use rather than only on file. The README opens
Changed:
  - panel: the sign-in and setup pages are now a column the width of their own
  - panel: the three monitoring pages — Deliveries, Mail queue, System log — are
Fixed:
  - panel: Deliveries now shows the subject as text rather than as its MIME
  - panel: table cells may now break inside a word, so no single long value can
  - panel: the Applications list on a domain page no longer comes apart. It was a

Full detail: CHANGELOG.md (0.4.0).

internal/web/handlers_auth.go

@@ -98,6 +98,7 @@ func (s *Server) handleLogin(w http.ResponseWriter, r *http.Request) {
 		// a failing form.
 		s.render(w, http.StatusOK, "login", map[string]any{
 			"Title":     "SelfPost — Sign in",
+			"Active":    "login",
 			"SetupHint": true,
 		})
 		return
@@ -115,9 +116,13 @@ func (s *Server) handleLogin(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *Server) renderLogin(w http.ResponseWriter, status int, formErr string) {
+	// Active names the page for the layout even though no navigation is drawn
+	// here: it is what puts page-login on <main>, which the stylesheet uses to
+	// give the signed-out pages a column the width of their own card.
 	s.render(w, status, "login", map[string]any{
-		"Title": "SelfPost — Sign in",
-		"Error": formErr,
+		"Title":  "SelfPost — Sign in",
+		"Active": "login",
+		"Error":  formErr,
 	})
 }