feat: enhance UI, refactor services, improve templates and tests

- Replace image_extractor with pdf_image_extractor service
- Enhance pi_client with expanded API capabilities
- Improve summarizer service with additional features
- Update admin routes with more endpoints
- Add login page template
- Enhance detail page with comprehensive layout
- Improve search and trends pages
- Update base template with additional elements
- Refactor tests for better coverage
- Add validate_summary script
- Update project configuration and dependencies

pyproject.toml

@@ -16,6 +16,8 @@ dependencies = [
     "python-dotenv>=1.0",
     "apscheduler>=3.10",
     "chromadb>=1.0",
+    "pymupdf>=1.25",
+    "itsdangerous>=2.2.0",
 ]
 
 [project.optional-dependencies]