Fix: User data becomes null (404) when logging in with Email ID which blocks project actions

[AashifAmeer]

Description

This PR fixes an issue where users logging in with their Email ID cannot create, update, delete projects, or perform other actions because the user data returns null (404). The issue happens because ClaimsIdentity (which stores user information like user ID, username, or roles after log in) is assigned with the username instead of the user ID. As a result:

• Logging in with a username works fine.
• Logging in with an Email ID fails because the user data is not found.

This fix ensures:

1. ClaimsIdentity is correctly assigned with the user ID during login, regardless of whether the user logs in with an Email ID or username.
2. The user ID is correctly retrieved from ClaimsIdentity when performing project actions.
3. Optimized project-related queries for better performance.

Changes Made

• Updated the login logic to assign ClaimsIdentity with the user ID instead of the username.
• Ensured user data is correctly retrieved when logging in with an Email ID.
• Added validation to correctly retrieve the user ID from ClaimsIdentity when performing project actions (create, update, delete).
• Optimized project-related queries using AnyAsync for efficient existence checks.

Fixes : #95

[cengique]

Works as intended, but deleting projects still broken.