Remove unused token schemas from the backend.

Eliminated redundant token-related schemas to simplify the codebase. These models were not actively utilized and their removal helps improve maintainability and reduce clutter in the project.

backend/app/schemas/token.py

@@ -1,54 +0,0 @@
-from typing import Optional
-from datetime import datetime
-from pydantic import BaseModel, Field
-
-
-class TokenBase(BaseModel):
-    """Base token schema with common attributes."""
-    token_type: str = Field(default="bearer", description="Type of authentication token")
-    expires_in: int = Field(description="Token expiration time in seconds")
-
-
-class Token(TokenBase):
-    """Schema for authentication response containing both access and refresh tokens."""
-    access_token: str = Field(description="JWT access token")
-    refresh_token: str = Field(description="JWT refresh token for obtaining new access tokens")
-
-
-class TokenPayload(BaseModel):
-    """Schema representing the decoded JWT token payload."""
-    sub: str = Field(description="Subject identifier (user ID)")
-    type: str = Field(description="Token type (access or refresh)")
-    exp: datetime = Field(description="Token expiration timestamp")
-    iat: datetime = Field(description="Token issued at timestamp")
-    jti: Optional[str] = Field(None, description="JWT ID - unique identifier for the token")
-
-
-class RefreshToken(BaseModel):
-    """Schema for refresh token requests."""
-    refresh_token: str = Field(
-        ...,
-        description="JWT refresh token used to obtain new access tokens"
-    )
-
-
-class TokenResponse(BaseModel):
-    """Schema for detailed token information response."""
-    access_token: str = Field(description="JWT access token")
-    refresh_token: str = Field(description="JWT refresh token")
-    token_type: str = Field(default="bearer")
-    expires_in: int = Field(description="Token expiration time in seconds")
-    scope: Optional[str] = Field(None, description="Token scope")
-    user_id: str = Field(description="ID of the authenticated user")
-
-    class Config:
-        json_schema_extra = {
-            "example": {
-                "access_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
-                "refresh_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
-                "token_type": "bearer",
-                "expires_in": 1800,
-                "scope": "read write",
-                "user_id": "123e4567-e89b-12d3-a456-426614174000"
-            }
-        }