fix: auto-install when profile specified via command line

Problem:
- Running 'curl ... | bash -s core' showed preview and waited for input
- User had to press Y to proceed even though profile was specified
- Defeats the purpose of one-command installation

Solution:
- Add NON_INTERACTIVE flag to track command-line profile usage
- Set NON_INTERACTIVE=true when profile argument provided
- Skip confirmation prompt when NON_INTERACTIVE=true
- Show 'Installing automatically (profile specified)...' message

Behavior:
Before:
  curl ... | bash -s core
  → Shows preview, waits for Y/n input

After:
  curl ... | bash -s core
  → Shows preview, installs automatically

Interactive mode still works:
  bash install.sh
  → Shows menu, asks for confirmation (as expected)

This makes profile-based installation truly one-command with no interaction needed.

install.sh

@@ -55,6 +55,7 @@ TEMP_DIR="/tmp/opencode-installer-$$"
 SELECTED_COMPONENTS=()
 INSTALL_MODE=""
 PROFILE=""
+NON_INTERACTIVE=false
 
 #############################################################################
 # Utility Functions
@@ -498,6 +499,12 @@ show_installation_preview() {
     [ ${#configs[@]} -gt 0 ] && echo -e "${CYAN}Config (${#configs[@]}):${NC} ${configs[*]##*:}"
     
     echo ""
+    
+    # Skip confirmation if profile was provided via command line
+    if [ "$NON_INTERACTIVE" = true ]; then
+        print_info "Installing automatically (profile specified)..."
+        perform_installation
+    else
         read -p "Proceed with installation? [Y/n]: " confirm
         
         if [[ $confirm =~ ^[Nn] ]]; then
@@ -506,6 +513,7 @@ show_installation_preview() {
         fi
         
         perform_installation
+    fi
 }
 
 #############################################################################
@@ -808,18 +816,22 @@ main() {
         core|--core)
             INSTALL_MODE="profile"
             PROFILE="core"
+            NON_INTERACTIVE=true
             ;;
         developer|--developer)
             INSTALL_MODE="profile"
             PROFILE="developer"
+            NON_INTERACTIVE=true
             ;;
         full|--full)
             INSTALL_MODE="profile"
             PROFILE="full"
+            NON_INTERACTIVE=true
             ;;
         advanced|--advanced)
             INSTALL_MODE="profile"
             PROFILE="advanced"
+            NON_INTERACTIVE=true
             ;;
         list|--list)
             check_dependencies