Add Asterisk configuration and diagnostics support

- Updated .env.example to include Asterisk templates path.
- Modified docker-compose.yml to mount the templates directory.
- Enhanced backend Dockerfile to copy templates into the container.
- Introduced Asterisk diagnostics functionality in asterisk_profiles.py, allowing for baseline checks and diagnostics reporting.
- Integrated Asterisk diagnostics into the device diagnostics workflow in graph.py.
- Added formatting for Asterisk baseline drift reports in diagnostic_format.py.
- Updated SKILL.md to document new config baseline drift feature for Asterisk.

This commit enhances the system's capabilities for managing Asterisk configurations and diagnostics, improving overall troubleshooting processes.

templates/asterisk/geneseasx/pjsip.conf.snippet

@@ -0,0 +1,13 @@
+; Golden reference snippet — GeneseasX Asterisk PJSIP (not executed; for human review).
+; Live checks use manifest.yaml required_lines against /etc/asterisk/pjsip.conf in container.
+
+[transport-udp]
+type=transport
+protocol=udp
+bind=0.0.0.0:5060
+local_net={{PHONE_SUBNET}}
+local_net={{VOIP_SUBNET}}
+external_media_address={{ASTERISK_IP}}
+external_signaling_address={{ASTERISK_IP}}
+
+; Endpoint includes vary by vessel — verify local_net on transport and per-endpoint if used.