feat: Add email settings management and templates functionality

- Implemented email settings configuration in the admin panel, allowing for SMTP settings and notification preferences.
- Created a new template for email settings with fields for SMTP host, port, username, password, sender address, and recipients.
- Added JavaScript functionality to handle loading, saving, and validating email settings.
- Introduced email templates management, enabling the listing, editing, and saving of email templates.
- Updated navigation to include links to email settings and templates.
- Added tests for email settings and templates to ensure proper functionality and validation.

tests/test_email_templates_api.py

@@ -1,4 +1,5 @@
 import importlib
+
 import pytest
 
 server_app_module = importlib.import_module("server.app")
@@ -11,33 +12,65 @@ def client():
         yield client
 
 
-def test_get_settings_returns_dict(client):
-    # Login as admin first
-    client.post('/auth/login', data={'username': 'admin', 'password': 'admin'})
-    resp = client.get('/admin/api/settings')
+def login(client):
+    return client.post('/auth/login', data={'username': 'admin', 'password': 'admin'})
+
+
+def test_email_template_list_requires_auth(client):
+    resp = client.get('/admin/api/email-templates')
+    assert resp.status_code == 302
+    assert resp.headers['Location'] == '/auth/login'
+
+
+def test_list_email_templates_returns_metadata(client):
+    login(client)
+    resp = client.get('/admin/api/email-templates')
     assert resp.status_code == 200
-    body = resp.get_json()
-    assert body['status'] == 'ok'
-    assert isinstance(body.get('settings'), dict)
+
+    payload = resp.get_json()
+    assert payload['status'] == 'ok'
+    assert isinstance(payload['templates'], list)
+    assert payload['templates'][0]['id'] == 'newsletter_confirmation'
 
 
-def test_update_and_get_newsletter_template(client):
-    key = 'newsletter_confirmation_template'
-    sample = '<p>Thanks for subscribing, {{email}}</p>'
-
-    # Update via PUT
-    # Login as admin first
-    client.post('/auth/login', data={'username': 'admin', 'password': 'admin'})
-
-    resp = client.put(f'/admin/api/settings/{key}', json={'value': sample})
+def test_get_email_template_returns_content(client):
+    login(client)
+    resp = client.get('/admin/api/email-templates/newsletter_confirmation')
     assert resp.status_code == 200
-    body = resp.get_json()
-    assert body['status'] == 'ok'
 
-    # Retrieve via GET and ensure the value is present
-    resp = client.get('/admin/api/settings')
+    payload = resp.get_json()
+    assert payload['status'] == 'ok'
+    template = payload['template']
+    assert template['id'] == 'newsletter_confirmation'
+    assert 'content' in template
+
+
+def test_update_email_template_persists_content(client):
+    login(client)
+    new_content = '<p>Updated template {{email}}</p>'
+
+    resp = client.put(
+        '/admin/api/email-templates/newsletter_confirmation',
+        json={'content': new_content},
+    )
     assert resp.status_code == 200
-    body = resp.get_json()
-    assert body['status'] == 'ok'
-    settings = body.get('settings') or {}
-    assert settings.get(key) == sample
+    payload = resp.get_json()
+    assert payload['status'] == 'ok'
+    assert payload['template']['content'] == new_content
+
+    # Fetch again to ensure persistence
+    resp_get = client.get('/admin/api/email-templates/newsletter_confirmation')
+    assert resp_get.status_code == 200
+    template = resp_get.get_json()['template']
+    assert template['content'] == new_content
+
+
+def test_update_email_template_requires_content(client):
+    login(client)
+    resp = client.put(
+        '/admin/api/email-templates/newsletter_confirmation',
+        json={'content': '   '},
+    )
+    assert resp.status_code == 400
+    payload = resp.get_json()
+    assert payload['status'] == 'error'