Replace hard-coded route strings with constants in auth/routes.py

[Refactor] Replace hard-coded route strings with constants in auth/routes.py

Description

The authentication routes file (app/auth/routes.py) contains hard-coded route name strings that should be replaced with constants for better maintainability.

Current Issues

File: app/auth/routes.py

Hard-coded strings found:

• 'admin.dashboard' (appears 2 times in login function)
• 'main.index' (appears 1 time in logout function)
• 'auth.login' (appears 1 time in login function)

Problems

• Typos only caught at runtime
• Difficult to refactor if route names change

Reference

• DEFAULT_AFTER_LOGIN = 'admin.dashboard'
• DEFAULT_AFTER_LOGOUT = 'main.index'

---

Labels: enhancement, refactoring, code-quality Scope: app/auth/routes.py