Enhance email previews, polish design, and fix focus trap

frontend/components/best-practices/AnalysisModal.tsx

@@ -263,7 +263,7 @@ export function AnalysisModal({
 
   return (
     <>
-      <Dialog open={open} onOpenChange={onOpenChange}>
+      <Dialog open={open} onOpenChange={onOpenChange} modal={!chatOpen}>
         <DialogContent
           showCloseButton={false}
           className="flex h-[85vh] max-h-[85vh] flex-col gap-0 overflow-hidden bg-[#141414] p-0 sm:max-w-[880px]"

internal/api/admin.go

@@ -395,6 +395,8 @@ func (h *AdminHandler) SendProblemReminder(w http.ResponseWriter, r *http.Reques
 		LogoURL:        logoURL,
 		SupportEmail:   emailAddressFromFrom(h.cfg.EmailFrom),
 		Tagline:        "Koder turns every problem into an instant feedback loop.",
+		PreviewTitle:   "Problem Reminder — Koder",
+		PreheaderText:  fmt.Sprintf("A new challenge is waiting: %s. Sharpen your skills with this short exercise.", problem.Title),
 	})
 	if err != nil {
 		slog.Error("admin: failed to render reminder template", "error", err)
@@ -560,6 +562,8 @@ func (h *AdminHandler) SendBestPracticesAnnouncement(w http.ResponseWriter, r *h
 		BestRuntimeMs:  bestRuntime,
 		DeveloperCount: len(authorSet),
 		TopSolutions:   topSolutions,
+		PreviewTitle:   "Discover Best Practices — Koder",
+		PreheaderText:  "See top-rated community solutions, get AI-powered code analysis, and learn from the best developers.",
 	})
 	if err != nil {
 		slog.Error("admin: failed to render best-practices template", "error", err)

internal/api/password_reset.go

@@ -333,6 +333,8 @@ If you didn't request this, you can safely ignore this email.
 		SupportEmail: emailAddressFromFrom(h.cfg.EmailFrom),
 		Tagline:      "Koder turns every problem into an instant feedback loop.",
 		ExpiresIn:    "1 hour",
+		PreviewTitle: "Reset Your Password — Koder",
+		PreheaderText: fmt.Sprintf("Hi %s, we received a password reset request for your Koder account. Click the link below to set a new password.", name),
 	})
 	if err != nil {
 		return "", &emailSendError{message: fmt.Sprintf("failed to render email template: %v", err)}