refactor(ssh): consolidate real_ssh into ssh, remove duplication

real_ssh was a separate service name pointing to the same template and
behaviour as ssh. Merged them: ssh is now the single real-OpenSSH service.

- Rename templates/real_ssh/ → templates/ssh/
- Remove decnet/services/real_ssh.py
- Deaddeck archetype updated: services=["ssh"]
- Merge test_real_ssh.py into test_ssh.py (includes deaddeck + logging tests)
- Drop decnet.services.real_ssh from test_build module list

templates/cowrie/honeyfs/etc/hosts

@@ -0,0 +1,5 @@
+127.0.0.1	localhost
+127.0.1.1	NODE_NAME
+::1		localhost ip6-localhost ip6-loopback
+ff02::1		ip6-allnodes
+ff02::2		ip6-allrouters