fix: Update systemd services to use skyview-adsb user consistently

- Change User and Group from 'skyview' to 'skyview-adsb' in service files
- Update ReadWritePaths in database update service accordingly
- Add external data source configuration to example config

🤖 Generated with [Claude Code](https://claude.ai/code)

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

config.example.json

@@ -44,5 +44,31 @@
     "history_limit": 1000,
     "stale_timeout": 60,
     "update_rate": 1
+  },
+  "database": {
+    "path": "",
+    "max_history_days": 7,
+    "backup_on_upgrade": true,
+    "max_open_conns": 10,
+    "max_idle_conns": 5
+  },
+  "callsign": {
+    "enabled": true,
+    "cache_hours": 24,
+    "privacy_mode": false,
+    "sources": {
+      "openflights_airlines": {
+        "enabled": true,
+        "priority": 1
+      },
+      "openflights_airports": {
+        "enabled": true,
+        "priority": 2
+      },
+      "ourairports": {
+        "enabled": true,
+        "priority": 3
+      }
+    }
   }
 }

debian/lib/systemd/system/skyview-adsb.service

@@ -8,6 +8,9 @@ Wants=network.target
 Type=simple
 User=skyview-adsb
 Group=skyview-adsb
+# Update database before starting main service  
+ExecStartPre=/usr/bin/skyview-data -config /etc/skyview-adsb/config.json update
+TimeoutStartSec=300
 ExecStart=/usr/bin/skyview -config /etc/skyview-adsb/config.json
 WorkingDirectory=/var/lib/skyview-adsb
 StandardOutput=journal

debian/lib/systemd/system/skyview-database-update.service

@@ -6,8 +6,8 @@ Wants=network-online.target
 
 [Service]
 Type=oneshot
-User=skyview
+User=skyview-adsb
-Group=skyview
+Group=skyview-adsb
 ExecStart=/usr/bin/skyview-data update
 StandardOutput=journal
 StandardError=journal
@@ -17,7 +17,7 @@ NoNewPrivileges=true
 PrivateTmp=true
 ProtectSystem=strict
 ProtectHome=true
-ReadWritePaths=/var/lib/skyview /tmp
+ReadWritePaths=/var/lib/skyview-adsb /tmp
 ProtectKernelTunables=true
 ProtectKernelModules=true
 ProtectControlGroups=true