Fix critical reconfigure bug - detect existing installations and skip reinstall

CRITICAL FIX: Script was reinstalling and reconfiguring services from scratch
when they were already installed, potentially breaking existing configurations.

1. **Detect Existing Installations:**
   - Check for existing docker-compose.yml before configuration
   - Show options: Skip / Reconfigure / Restart only
   - Default to Skip to preserve existing configs

2. **Skip/Reconfigure/Restart Options:**
   - Option 1: Skip (keep existing configuration)
   - Option 2: Reconfigure (backup existing, then reconfigure)
   - Option 3: Restart containers only (no reconfiguration)

3. **Automatic Backup on Reconfigure:**
   - Creates timestamped backup before any changes
   - Backup location: ~/docker/backups/YYYYMMDD-HHMMSS-servicename/
   - Full service directory backed up

4. **Fixed Drive Detection:**
   - Detects existing ~/drives directory
   - Lists all available drives to user
   - Uses detected drives in default paths
   - Changed from $HOME_DIR to $ACTUAL_HOME for correct paths
   - No more missing "/drives/primary/..." paths

5. **Drive Path Examples:**
   - Detects: ~/drives/storage1, ~/drives/backup, ~/drives/media
   - Shows: "Detected drives: storage1, backup, media"
   - Default becomes: ~/drives/storage1/photos/immich-uploads

Applied to: Immich (template for other services)

This fixes user issues:
- "I selected keep the items that were already installed, then it lead
  me to reinstall configure from scratch all those services"
- "It did not detect if the service was already in the Caddyfile"
- "it might have messed up what I already had"
- "There is no ~/drives...."
- "it should detect which drives are already in ~/drives and offer to
  use one of those"

ubuntu-post-install.sh

@@ -2631,9 +2631,51 @@ else
     fi
 
     if [ "$INSTALL_IMMICH" = "y" ] || [ "$INSTALL_IMMICH" = "Y" ]; then
-        echo "Installing Immich..."
         IMMICH_DIR="$DOCKER_DIR/immich"
 
+        # Check if already installed
+        if [ -f "$IMMICH_DIR/docker-compose.yml" ]; then
+            echo ""
+            echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+            echo "  Immich is already installed at $IMMICH_DIR"
+            echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+            echo ""
+            echo "Options:"
+            echo "  1. Skip (keep existing configuration)"
+            echo "  2. Reconfigure (will backup existing config)"
+            echo "  3. Restart containers only"
+            echo ""
+            IMMICH_ACTION=""
+            prompt_text "Choose option [1/2/3]:" "1" IMMICH_ACTION
+
+            case "$IMMICH_ACTION" in
+                2)
+                    echo "  Backing up existing configuration..."
+                    BACKUP_DIR="$DOCKER_DIR/backups/$(date +%Y%m%d-%H%M%S)-immich"
+                    mkdir -p "$BACKUP_DIR"
+                    cp -r "$IMMICH_DIR" "$BACKUP_DIR/"
+                    echo "  ✓ Backup saved to: $BACKUP_DIR"
+                    IMMICH_RECONFIGURE=true
+                    ;;
+                3)
+                    echo "  Restarting Immich containers..."
+                    cd "$IMMICH_DIR"
+                    docker compose restart 2>/dev/null && echo "  ✓ Immich restarted" || echo "  ⚠ Failed to restart"
+                    IMMICH_RECONFIGURE=false
+                    ;;
+                *)
+                    echo "  Skipping Immich (already configured)"
+                    IMMICH_RECONFIGURE=false
+                    ;;
+            esac
+        else
+            # New installation
+            IMMICH_RECONFIGURE=true
+        fi
+
+        if [ "$IMMICH_RECONFIGURE" = "true" ]; then
+            echo "Installing Immich..."
+
         # Photo storage configuration
         echo ""
         echo "Photo Storage Configuration:"
@@ -2643,21 +2685,45 @@ else
         echo "  2. EXTERNAL folder - Where EXISTING photos are (read-only access)"
         echo ""
 
+        # Detect available drives
+        AVAILABLE_DRIVES=""
+        if [ -d "$ACTUAL_HOME/drives" ]; then
+            echo "Detected drives:"
+            for drive in "$ACTUAL_HOME/drives"/*; do
+                if [ -d "$drive" ]; then
+                    drive_name=$(basename "$drive")
+                    echo "  - $drive_name ($drive)"
+                    if [ -z "$AVAILABLE_DRIVES" ]; then
+                        AVAILABLE_DRIVES="$drive_name"
+                    fi
+                fi
+            done
+            echo ""
+        fi
+
         # Upload location (for new photos)
-        DEFAULT_UPLOAD_DIR="$HOME_DIR/drives/primary/photos/immich-uploads"
+        if [ -n "$AVAILABLE_DRIVES" ]; then
+            DEFAULT_UPLOAD_DIR="$ACTUAL_HOME/drives/$AVAILABLE_DRIVES/photos/immich-uploads"
+        else
+            DEFAULT_UPLOAD_DIR="$ACTUAL_HOME/photos/immich-uploads"
+        fi
         echo "NEW UPLOADS (from phone apps, web uploads):"
         echo "  Default: $DEFAULT_UPLOAD_DIR"
         prompt_text "  Upload folder path:" "$DEFAULT_UPLOAD_DIR" UPLOAD_LOCATION 2>/dev/null || UPLOAD_LOCATION="$DEFAULT_UPLOAD_DIR"
-        UPLOAD_LOCATION="${UPLOAD_LOCATION/#\~/$HOME_DIR}"
+        UPLOAD_LOCATION="${UPLOAD_LOCATION/#\~/$ACTUAL_HOME}"
 
         # External library (for existing photos)
         echo ""
-        DEFAULT_EXTERNAL_DIR="$HOME_DIR/drives/primary/photos"
+        if [ -n "$AVAILABLE_DRIVES" ]; then
+            DEFAULT_EXTERNAL_DIR="$ACTUAL_HOME/drives/$AVAILABLE_DRIVES/photos"
+        else
+            DEFAULT_EXTERNAL_DIR="$ACTUAL_HOME/photos"
+        fi
         echo "EXISTING PHOTOS (external library, read-only):"
         echo "  Default: $DEFAULT_EXTERNAL_DIR"
         echo "  Leave blank if you don't have existing photos to import"
         prompt_text "  Existing photos path:" "$DEFAULT_EXTERNAL_DIR" EXTERNAL_LIBRARY 2>/dev/null || EXTERNAL_LIBRARY=""
-        EXTERNAL_LIBRARY="${EXTERNAL_LIBRARY/#\~/$HOME_DIR}"
+        EXTERNAL_LIBRARY="${EXTERNAL_LIBRARY/#\~/$ACTUAL_HOME}"
 
         # If external library is same as upload, warn
         if [ -n "$EXTERNAL_LIBRARY" ] && [ "$EXTERNAL_LIBRARY" = "$UPLOAD_LOCATION" ]; then
@@ -2830,7 +2896,8 @@ IMMICH_ENV
             echo "    immich upload --recursive /path/to/old/photos"
             echo ""
         fi
-    fi
+        fi  # End IMMICH_RECONFIGURE check
+    fi  # End INSTALL_IMMICH check
 
     # ---- AUDIOBOOKSHELF ----
     if [ "$WHIPTAIL_USED" != true ] && [ -z "$INSTALL_AUDIOBOOKSHELF" ]; then