Rename Debian package from skyview to skyview-adsb

The official Debian repositories already contain a package named
"skyview" which is associated with NASA's SkyView Virtual Observatory
(https://skyview.gsfc.nasa.gov/), a tool for astronomical data
visualization.

To avoid package naming conflicts and potential confusion for users,
this commit renames our ADS-B aircraft tracking application package
to "skyview-adsb". This clearly indicates the package's purpose
(ADS-B tracking) while maintaining the SkyView brand identity.

Changes:
- Package name: skyview → skyview-adsb
- System user/group: skyview → skyview-adsb
- Config directory: /etc/skyview → /etc/skyview-adsb
- Data directory: /var/lib/skyview → /var/lib/skyview-adsb
- Log directory: /var/log/skyview → /var/log/skyview-adsb
- Systemd service: skyview.service → skyview-adsb.service
- Documentation path: /usr/share/doc/skyview → /usr/share/doc/skyview-adsb

The binaries (/usr/bin/skyview and /usr/bin/beast-dump) remain
unchanged as they don't conflict at the filesystem level.

This ensures clean installation alongside any existing skyview
packages and prevents apt/dpkg conflicts during installation.

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

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

debian/DEBIAN/prerm

@@ -4,12 +4,12 @@ set -e
 case "$1" in
     remove|upgrade|deconfigure)
         # Stop and disable the service
-        if systemctl is-active --quiet skyview.service; then
-            systemctl stop skyview.service
+        if systemctl is-active --quiet skyview-adsb.service; then
+            systemctl stop skyview-adsb.service
         fi
         
-        if systemctl is-enabled --quiet skyview.service; then
-            systemctl disable skyview.service
+        if systemctl is-enabled --quiet skyview-adsb.service; then
+            systemctl disable skyview-adsb.service
         fi
         ;;
 esac