Auto-install missing dependencies without additional prompt

Previously, install.sh would:
1. Ask "Install DVD authoring tools?"
2. Then ask again "Install missing dependencies now?"

Now it automatically installs any missing dependencies after the
user confirms they want DVD tools, eliminating the redundant prompt.

Changes:
- Removed second confirmation prompt for dependency installation
- Automatically installs missing deps when detected
- Shows clear message: "Missing dependencies: ... Installing..."

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

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

scripts/install.sh

@@ -175,11 +175,9 @@ else
 
     install_deps=false
     if [ ${#missing_deps[@]} -gt 0 ]; then
-        echo -e "${YELLOW}WARNING${NC} Missing dependencies: ${missing_deps[*]}"
-        read -p "Install missing dependencies now? [y/N]: " install_choice
-        if [[ "$install_choice" =~ ^[Yy]$ ]]; then
-            install_deps=true
-        fi
+        echo -e "${YELLOW}⚠${NC} Missing dependencies: ${missing_deps[*]}"
+        echo "Installing missing dependencies..."
+        install_deps=true
     else
         echo -e "${GREEN}✓${NC} All authoring dependencies found"
     fi