feat(auth): add active sessions management

- store refresh session metadata in redis (ip/user-agent/created_at)

- add auth APIs: list sessions, revoke one, revoke all

- add web privacy UI for active sessions

app/auth/schemas.py

@@ -58,3 +58,10 @@ class AuthUserResponse(BaseModel):
     email_verified: bool
     created_at: datetime
     updated_at: datetime
+
+
+class SessionRead(BaseModel):
+    jti: str
+    created_at: datetime
+    ip_address: str | None = None
+    user_agent: str | None = None