Remove unused templates for newsletter creation, settings, and submissions; update unsubscribe confirmation link; add tests for email templates API.

server/routes/embed.py

@@ -1,8 +1,7 @@
 """Embeddable forms routes."""
 from __future__ import annotations
 
-from flask import Blueprint, render_template, send_from_directory
-import os
+from flask import Blueprint, render_template
 
 bp = Blueprint("embed", __name__)
 
@@ -17,10 +16,3 @@ def contact_form():
 def newsletter_form():
     """Serve the embeddable newsletter subscription form."""
     return render_template("embed_newsletter.html")
-
-
-@bp.route("/static/css/styles.css", methods=["GET"])
-def serve_css():
-    """Serve the unified CSS file."""
-    static_dir = os.path.join(os.path.dirname(__file__), '..', '..', 'static')
-    return send_from_directory(static_dir, 'css/styles.css')