fix: resolve install script unbound variables and add update command

Addresses #450, #451, #406

- Initialize all variables at top of script to prevent "unbound variable" errors with set -u
  - BUILD_FROM_SOURCE, SKIP_DOWNLOAD, IN_CONTAINER, IN_DOCKER now set at line 20-27
  - ENABLE_AUTO_UPDATES, FORCE_VERSION, FORCE_CHANNEL, SOURCE_BRANCH also moved to top
  - Removed duplicate assignments from argument parsing section

- Restore /bin/update command creation for ProxmoxVE LXC installations
  - Creates update script that re-runs install.sh for easy updates
  - Allows backend to properly detect ProxmoxVE deployment type
  - Users can now run "update" in LXC console as documented

- Update deployment detection to recognize install.sh in update command
  - Previously only looked for legacy "pulse.sh" reference
  - Now checks for both pulse.sh and install.sh

install.sh

@@ -19,6 +19,12 @@ SERVICE_NAME="pulse"
 GITHUB_REPO="rcourtman/Pulse"
 BUILD_FROM_SOURCE=false
 SKIP_DOWNLOAD=false
+IN_CONTAINER=false
+IN_DOCKER=false
+ENABLE_AUTO_UPDATES=false
+FORCE_VERSION=""
+FORCE_CHANNEL=""
+SOURCE_BRANCH="main"
 
 # Wrapper for systemctl commands that might hang in unprivileged containers
 safe_systemctl() {
@@ -1453,15 +1459,29 @@ setup_directories() {
 }
 
 setup_update_command() {
-    # Function kept for compatibility but no longer creates update command
-    # Community Scripts installations have their own update mechanism at /bin/update
-    # Native installations should update using: curl -fsSL ... | bash
-    
+    # Create update command at /bin/update for ProxmoxVE LXC detection
+    # This allows the backend to detect ProxmoxVE installations
+    cat > /bin/update <<'EOF'
+#!/usr/bin/env bash
+# Pulse update command
+# This script re-runs the Pulse installer to update to the latest version
+
+set -e
+
+echo "Updating Pulse..."
+curl -fsSL https://raw.githubusercontent.com/rcourtman/Pulse/main/install.sh | bash
+
+echo ""
+echo "Update complete! Pulse will restart automatically."
+EOF
+
+    chmod +x /bin/update
+
     # Ensure /usr/local/bin is in PATH for all users
     if ! grep -q '/usr/local/bin' /etc/profile 2>/dev/null; then
         echo 'export PATH="/usr/local/bin:$PATH"' >> /etc/profile
     fi
-    
+
     # Also add to bash profile if it exists
     if [[ -f /etc/bash.bashrc ]] && ! grep -q '/usr/local/bin' /etc/bash.bashrc 2>/dev/null; then
         echo 'export PATH="/usr/local/bin:$PATH"' >> /etc/bash.bashrc
@@ -2372,13 +2392,6 @@ reset_pulse() {
 }
 
 # Parse command line arguments
-FORCE_VERSION=""
-FORCE_CHANNEL=""
-SOURCE_BRANCH="main"
-IN_CONTAINER=false
-IN_DOCKER=false
-ENABLE_AUTO_UPDATES=false
-
 while [[ $# -gt 0 ]]; do
     case $1 in
         --uninstall)

internal/updates/version.go

@@ -238,7 +238,7 @@ func GetDeploymentType() string {
 	if fileExists("/bin/update") {
 		// Read file directly instead of using exec.Command
 		data, err := os.ReadFile("/bin/update")
-		if err == nil && strings.Contains(string(data), "pulse.sh") {
+		if err == nil && (strings.Contains(string(data), "pulse.sh") || strings.Contains(string(data), "install.sh")) {
 			return "proxmoxve"
 		}
 	}