Fix broken password reset email templates

Both templates called `@user.password_reset_token` and
`@user.password_reset_token_expires_in`, which don't exist —
`generates_token_for` only adds class-level helpers, not instance
accessors. Every password reset email was failing at render time.
Use `generate_token_for(:password_reset)` and a literal expiry string
matching the 1-hour TTL on the token.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/views/passwords_mailer/reset.html.erb

@@ -1,6 +1,6 @@
 <p>
   You can reset your password on
-  <%= link_to "this password reset page", edit_password_url(@user.password_reset_token) %>.
+  <%= link_to "this password reset page", edit_password_url(@user.generate_token_for(:password_reset)) %>.
 
-  This link will expire in <%= distance_of_time_in_words(0, @user.password_reset_token_expires_in) %>.
+  This link will expire in 1 hour.
 </p>

app/views/passwords_mailer/reset.text.erb

@@ -1,4 +1,4 @@
 You can reset your password on
-<%= edit_password_url(@user.password_reset_token) %>
+<%= edit_password_url(@user.generate_token_for(:password_reset)) %>
 
-This link will expire in <%= distance_of_time_in_words(0, @user.password_reset_token_expires_in) %>.
+This link will expire in 1 hour.