[codex] import token_data from codex-login directly (#15903)

## Why
`token_data` is owned by `codex-login`, but `codex-core` was still
re-exporting it. That let callers pull auth token types through
`codex-core`, which keeps otherwise unrelated crates coupled to
`codex-core` and makes `codex-core` more of a build-graph bottleneck.

## What changed
- remove the `codex-core` re-export of `codex_login::token_data`
- update the remaining `codex-core` internals that used
`crate::token_data` to import `codex_login::token_data` directly
- update downstream callers in `codex-rs/chatgpt`,
`codex-rs/tui_app_server`, `codex-rs/app-server/tests/common`, and
`codex-rs/core/tests` to import `codex_login::token_data` directly
- add explicit `codex-login` workspace dependencies and refresh lock
metadata for crates that now depend on it directly

## Validation
- `cargo test -p codex-chatgpt --locked`
- `just argument-comment-lint`
- `just bazel-lock-update`
- `just bazel-lock-check`

## Notes
- attempted `cargo test -p codex-core --locked` and `cargo test -p
codex-core auth_refresh --locked`, but both ran out of disk while
linking `codex-core` test binaries in the local environment

codex-rs/app-server/tests/common/auth_fixtures.rs

@@ -10,8 +10,8 @@ use codex_app_server_protocol::AuthMode;
 use codex_core::auth::AuthCredentialsStoreMode;
 use codex_core::auth::AuthDotJson;
 use codex_core::auth::save_auth;
-use codex_core::token_data::TokenData;
-use codex_core::token_data::parse_chatgpt_jwt_claims;
+use codex_login::token_data::TokenData;
+use codex_login::token_data::parse_chatgpt_jwt_claims;
 use serde_json::json;
 
 /// Builder for writing a fake ChatGPT auth.json in tests.