Add adaptive text overlay to story posts with smart sizing

Implement automatic text overlay for stories, burning text into the bottom 25% of the image with adaptive font sizing (24-72px) using node-canvas, preserving aspect ratio, wrapping text, truncating long text, and adding a semi-transparent black background.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: ae4037a0-2a6f-4530-9bac-79b543286bda
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Event-Id: 746e211c-5491-469d-b1ad-02dd831ee078
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/397bca8c-984f-43ff-841a-10897aeb8140/ae4037a0-2a6f-4530-9bac-79b543286bda/f2EnhiB

replit.md

@@ -11,6 +11,7 @@ Preferred communication style: Simple, everyday language.
 ## Recent Changes
 
 ### November 17, 2025
+- **Story Text Overlay with Adaptive Sizing**: Implemented automatic text overlay on Instagram and Facebook stories with intelligent font size adaptation. When publishing a story with text content, the system now generates a composite image with the text burned into the bottom 25% of the image. Features: (1) Adaptive font sizing (24-72px) that automatically adjusts based on text length to fit within the text box, (2) Aspect ratio preservation for source images (centered with black letterboxing if needed to maintain 9:16 story format), (3) Automatic text wrapping with line breaks on word boundaries, (4) Ellipsis truncation for extremely long text that exceeds available space, (5) Semi-transparent black background (60% opacity) behind text for readability. Implementation uses Canvas (node-canvas) for image composition in `imageProcessor.addTextToStoryImage()`, with the generated image uploaded to Cloudinary in a dedicated `social-flow/stories` folder before publication. This ensures text appears correctly on published stories since Facebook/Instagram APIs don't support text overlays natively. The text box reserves 25% of the image height with 40px padding, and font size reduces in 2px increments until text fits or reaches the 24px minimum.
 - **AI Assistant Model Loading Fix**: Fixed bug preventing non-admin users from accessing the AI assistant feature. Problem: The AI chat component (`ai-chat.tsx`) was querying `/api/ai/models` which requires admin privileges (`requireAdmin`), causing model list to fail loading for regular users. Solution: Changed the component to use `/api/openrouter/models` endpoint instead, which only requires authentication (`requireAuth`). Updated data structure access from `modelsData?.models` to `modelsData?.data` to match the OpenRouter API response format `{ data: OpenRouterModel[] }`. This fix enables all authenticated users to load the model list and use the AI assistant feature. The endpoint `/api/openrouter/models` was already being used in Settings page for the same purpose, ensuring consistency across the application.
 
 ### November 5, 2025