Fix Debian package build issues

- Remove debian/compat file (conflicts with Build-Depends)
- Fix debian/install to use correct readme.md filename
- Update verify-deb.sh to mark debian/compat as optional
- Add -Zgzip flag to dpkg-buildpackage for compatibility
  (uses gzip instead of zstd for better compatibility)
- Update verify-deb.sh to check optional vs required files

Package now builds and installs successfully on systems
without zstd support.

scripts/verify-deb.sh

@@ -60,12 +60,16 @@ REQUIRED_FILES=(
     "debian/postinst"
     "debian/prerm"
     "debian/postrm"
-    "debian/compat"
     "debian/sensorpajen.service"
     "src/sensorpajen/main.py"
     "pyproject.toml"
 )
 
+# Optional files (debian/compat is now optional - use Build-Depends instead)
+OPTIONAL_FILES=(
+    "debian/compat"
+)
+
 ALL_FILES_OK=1
 for file in "${REQUIRED_FILES[@]}"; do
     echo -n "  $file... "
@@ -77,6 +81,16 @@ for file in "${REQUIRED_FILES[@]}"; do
     fi
 done
 
+# Check optional files
+for file in "${OPTIONAL_FILES[@]}"; do
+    echo -n "  $file... "
+    if [ -f "$file" ]; then
+        echo -e "${GREEN}OK${NC}"
+    else
+        echo -e "${YELLOW}OPTIONAL${NC}"
+    fi
+done
+
 if [ $ALL_FILES_OK -eq 0 ]; then
     echo -e "${RED}Some required files are missing!${NC}"
     exit 1
@@ -94,10 +108,10 @@ echo "Cleaning previous builds..."
 rm -f ../*.deb ../*.build ../*.buildinfo ../*.changes
 rm -rf debian/.debhelper debian/sensorpajen debian/files
 
-# Build the package
+# Build the package with gzip compression (for compatibility)
 echo "Building Debian package..."
 echo "======================================================================"
-dpkg-buildpackage -us -uc -b
+dpkg-buildpackage -us -uc -b -Zgzip
 
 if [ $? -ne 0 ]; then
     echo -e "${RED}Build failed!${NC}"