Implement Template Gallery Interface

[aydarng]

Create a user-friendly interface for browsing, searching, and loading templates from the template library.
Tasks

• Create TemplateGallery component (src/components/templates/TemplateGallery.tsx)
• Create TemplateCard component (src/components/templates/TemplateCard.tsx)
• Create TemplatePreview component for mini-graph visualization
• Implement template loading functionality
• Add Templates tab to main navigation
• Implement search functionality (by name, description, tags)
• Implement filter functionality (by category, complexity)
• Add template card layout with metadata display
• Create TemplatesPage component (src/pages/TemplatesPage.tsx)

Features

• Template Grid: Visual cards showing template information
• Search & Filter:
  • Search by name/description
  • Filter by tags
• Template Cards: Display name, description, category, estimated time, complexity
• Load Template: Click to load workflow + config into main interface
• Preview: Show mini-graph preview of workflow structure

Acceptance Criteria

• Users can browse all available templates in a grid layout
• Users can search templates by name, description, or tags
• Users can filter templates by category and complexity
• Users can click to load a template into the main workflow interface
• Template cards display all relevant metadata
• Mini-graph preview shows workflow structure
• Templates tab is accessible from main navigation