feat: ensure consistent filename IDs across script steps

img_api_generate.sh

@@ -286,12 +286,15 @@ validate_inputs() {
 # OUTPUT FILENAME GENERATION
 # ============================================================================
 
+_GENERATED_TIMESTAMP=""
+
 generate_output_filename() {
     local suffix="${1:-}"
-    local timestamp
+    if [[ -z "$_GENERATED_TIMESTAMP" ]]; then
-    timestamp=$(date +%Y%m%d_%H%M%S)
+        _GENERATED_TIMESTAMP=$(date +%Y%m%d_%H%M%S)
+    fi
     local seed_part="${SEED:-0}"
-    local base="img_${MODEL}_${timestamp}_${seed_part}"
+    local base="img_${MODEL}_${_GENERATED_TIMESTAMP}_${seed_part}"
 
     if [[ -n "$suffix" ]]; then
         echo "${base}_${suffix}.png"
@@ -970,6 +973,9 @@ main() {
     # Validate inputs
     validate_inputs
 
+    # Initialize timestamp for consistent naming across subshells
+    _GENERATED_TIMESTAMP=$(date +%Y%m%d_%H%M%S)
+
     # Banner
     print_banner "${PALETTE} Pivoine Image Generator ${SPARKLES}"
 
@@ -1043,9 +1049,14 @@ main() {
             local ext="${OUTPUT_FILE##*.}"
             local base="${OUTPUT_FILE%.*}"
             upscale_path="${base}_upscaled.${ext}"
+        else
+            # Include faceswap in name if it was performed
+            if [[ -n "${faceswap_path:-}" && -f "${faceswap_path}" ]]; then
+                upscale_path="$(generate_output_filename "faceswap_upscaled")"
             else
                 upscale_path="$(generate_output_filename "upscaled")"
             fi
+        fi
 
         realesrgan_upscale "$final_input" upscale_path || exit 1