Implement Login UI

<img width="604" height="574" alt="Image" src="https://github.com/user-attachments/assets/c480c249-6c0b-4ce3-88f1-50ea594ec1e5" />

Description:
Build the user login page.

Tasks:

• [ ] Create src/pages/auth/LoginPage.jsx
• [ ] Form fields: Email, Password with show/hide toggle
• [ ] "Forgot Password?" link below the password field
• [ ] Submit button shows loading state
• [ ] On success, dispatch setCredentials and redirect to /dashboard
• [ ] Display 401 and 403 errors clearly (e.g. "Unverified account — please check your email")

Acceptance Criteria:
Successful login redirects to dashboard; wrong credentials show an error; unverified accounts show a specific message.

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