fix: correct DKIM path (opendkim, not rspamd) in tools tasks

docker-mailserver uses opendkim by default; generated keys go to
config/opendkim/keys/<domain>/mail.{private,txt}, not rspamd/dkim/.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

roles/tools/tasks/main.yml

@@ -84,7 +84,7 @@
 
 - name: Check if DKIM key exists
   ansible.builtin.stat:
-    path: "{{ tools_root }}/mailserver/config/rspamd/dkim/{{ domain_base }}.private"
+    path: "{{ tools_root }}/mailserver/config/opendkim/keys/{{ domain_base }}/mail.private"
   register: dkim_key
 
 - name: Generate DKIM key
@@ -95,7 +95,7 @@
 
 - name: Show DKIM DNS record
   ansible.builtin.command: >
-    cat {{ tools_root }}/mailserver/config/rspamd/dkim/{{ domain_base }}.txt
+    cat {{ tools_root }}/mailserver/config/opendkim/keys/{{ domain_base }}/mail.txt
   when: dkim_generated is changed
   register: dkim_record