Integrate email notifications into signup and login (#38)

backend/notifications/README.md

@@ -40,7 +40,8 @@ Multiple service workers can safely compete for jobs through atomic claims.
 
 ## Templates and parameters
 
-See `templates.example.json`. Parameters use Go template map syntax such as
+See `templates.example.json`, including the `auth.activation` and `auth.login`
+English/Russian templates used by [product authentication](../../docs/auth-notifications.md). Parameters use Go template map syntax such as
 `{{.first_name}}`. Each revision declares the exact allowed parameter names and
 locale-specific content. Missing/extra parameters, unknown revisions/locales and
 invalid content are rejected before acceptance. Empty locale uses the default.

backend/notifications/templates.example.json

@@ -3,7 +3,11 @@
     "id": "exchange.completed",
     "version": "1",
     "default_locale": "en",
-    "parameters": ["first_name", "amount", "currency"],
+    "parameters": [
+      "first_name",
+      "amount",
+      "currency"
+    ],
     "locales": {
       "en": {
         "subject": "Your exchange is complete",
@@ -11,5 +15,45 @@
         "text": "Hi {{.first_name}}, your exchange of {{.amount}} {{.currency}} is complete."
       }
     }
+  },
+  {
+    "id": "auth.activation",
+    "version": "1",
+    "default_locale": "en",
+    "parameters": [
+      "url"
+    ],
+    "locales": {
+      "en": {
+        "subject": "Verify your SXCHNGE email",
+        "text": "Confirm your email: {{.url}}\nThis link expires in 24 hours. If you did not sign up, ignore this email.",
+        "html": "<p>Confirm your email to finish signing up.</p><p><a href=\"{{.url}}\">Verify email</a></p><p>This link expires in 24 hours. If you did not sign up, ignore this email.</p>"
+      },
+      "ru": {
+        "subject": "Подтвердите почту SXCHNGE",
+        "text": "Подтвердите почту: {{.url}}\nСсылка действует 24 часа. Если вы не регистрировались, проигнорируйте письмо.",
+        "html": "<p><a href=\"{{.url}}\">Подтвердить почту</a></p><p>Ссылка действует 24 часа. Если вы не регистрировались, проигнорируйте письмо.</p>"
+      }
+    }
+  },
+  {
+    "id": "auth.login",
+    "version": "1",
+    "default_locale": "en",
+    "parameters": [
+      "code"
+    ],
+    "locales": {
+      "en": {
+        "subject": "Your SXCHNGE login code",
+        "text": "Your login code is {{.code}}. It expires in 10 minutes. Never share this code.",
+        "html": "<p>Your login code is <strong>{{.code}}</strong>.</p><p>It expires in 10 minutes. Never share this code.</p>"
+      },
+      "ru": {
+        "subject": "Код входа SXCHNGE",
+        "text": "Ваш код входа: {{.code}}. Он действует 10 минут. Никому не сообщайте код.",
+        "html": "<p>Ваш код входа: <strong>{{.code}}</strong>.</p><p>Он действует 10 минут. Никому не сообщайте код.</p>"
+      }
+    }
   }
 ]