feat: add account self-service safeguards

backend/apps/accounts/schemas.py

@@ -40,6 +40,8 @@ class CurrentUserOut(Schema):
     username: str
     display_name: str
     email: str
+    last_login: datetime | None = None
+    date_joined: datetime
     is_superuser: bool
     roles: list[RoleOut]
     user_groups: list[UserGroupOut]
@@ -73,6 +75,33 @@ class UserUpdateIn(Schema):
     is_active: bool | None = None
 
 
+class ProfileUpdateIn(Schema):
+    display_name: str | None = None
+    email: str | None = None
+
+
+class PasswordChangeIn(Schema):
+    current_password: str
+    new_password: str
+
+
+class ProfileActivityOut(Schema):
+    id: int
+    ticket_id: int
+    ticket_no: str
+    ticket_title: str
+    event_type: str
+    created_at: datetime
+
+
+class ProfileStatsOut(Schema):
+    created_total: int
+    active_assigned: int
+    completed_30d: int
+    completion_rate: float
+    recent_activity: list[ProfileActivityOut] = []
+
+
 class PasswordResetIn(Schema):
     password: str