Move auth code into login crate (#15150)

- Move the auth implementation and token data into codex-login.
- Keep codex-core re-exporting that surface from codex-login for
existing callers.

---------

Co-authored-by: Codex <noreply@openai.com>

codex-rs/core/src/error.rs

@@ -9,6 +9,8 @@ use chrono::Datelike;
 use chrono::Local;
 use chrono::Utc;
 use codex_async_utils::CancelErr;
+pub use codex_login::auth::RefreshTokenFailedError;
+pub use codex_login::auth::RefreshTokenFailedReason;
 use codex_protocol::ThreadId;
 use codex_protocol::protocol::CodexErrorInfo;
 use codex_protocol::protocol::ErrorEvent;
@@ -261,30 +263,6 @@ impl std::fmt::Display for ResponseStreamFailed {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Error)]
-#[error("{message}")]
-pub struct RefreshTokenFailedError {
-    pub reason: RefreshTokenFailedReason,
-    pub message: String,
-}
-
-impl RefreshTokenFailedError {
-    pub fn new(reason: RefreshTokenFailedReason, message: impl Into<String>) -> Self {
-        Self {
-            reason,
-            message: message.into(),
-        }
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum RefreshTokenFailedReason {
-    Expired,
-    Exhausted,
-    Revoked,
-    Other,
-}
-
 #[derive(Debug)]
 pub struct UnexpectedResponseError {
     pub status: StatusCode,