Fixes issue where PromptManager Gallery showed identical prompts for all
images when using workflows like Flux models that generate multiple images
with the same base workflow.
**Problem:**
- Gallery relied solely on PNG metadata extraction for prompt display
- Images generated from same workflow (e.g., Flux models) contained
identical workflow metadata but should show different prompts
- Navigation between images didn't update prompt information correctly
**Solution:**
1. **Enhanced metadata extraction:**
- Improved parseWorkflowData() to handle more ComfyUI node types
- Added support for PromptManagerText, UNETLoader, DualCLIPLoader
- Better negative prompt detection patterns
- Enhanced sampling parameter extraction
2. **New API endpoint:**
- Added GET /prompt_manager/images/prompt/{image_path}
- Queries database for actual prompt used during generation
- Provides accurate prompt data linked to specific images
3. **Hybrid metadata loading:**
- Primary: Query database for linked prompt data
- Fallback: Extract from PNG metadata if no database record
- Combines database prompts with PNG technical parameters
**Changes:**
- py/api.py: Added get_image_prompt() endpoint and route
- web/gallery.html: Enhanced loadImageMetadata() and parseWorkflowData()
**Result:**
- Gallery now displays correct, unique prompts for each image
- Prompt information updates properly when navigating between images
- Generation data refreshes correctly with prev/next navigation
- Maintains backward compatibility for images without database records
Resolves user-reported issue with Flux.1_Krea_Dev_workflow.json where
all images showed identical prompts in gallery view.