feat: Add LaTeX template-based form filling for G2210-11

Replace unreliable visual overlay mode with precise LaTeX templates:

- Add LaTeX template for G2210-11 (Ärztlicher Befundbericht der WAG)
- Create Python Flask backend for LaTeX compilation (latex_service.py, server.py)
- Add frontend latexService.ts for API communication
- Update ReviewPanel with LaTeX mode toggle and preview
- Enhance Gemini prompts with G2210-11 specific field extraction
- Add Dockerfile with TeX Live for Railway deployment
- Update railway.toml to use Docker builder

The LaTeX approach ensures accurate field placement and proper
formatting for German medical/insurance forms.

https://claude.ai/code/session_016pQhdznHZ74Fpkvwr3cLBq

railway.toml

@@ -1,9 +1,9 @@
 [build]
-builder = "nixpacks"
+builder = "dockerfile"
+dockerfilePath = "Dockerfile"
 
 [deploy]
-startCommand = "npm start"
 healthcheckPath = "/"
-healthcheckTimeout = 100
+healthcheckTimeout = 300
 restartPolicyType = "on_failure"
 restartPolicyMaxRetries = 3