extract models manager and related ownership from core (#16508)

## Summary
- split `models-manager` out of `core` and add `ModelsManagerConfig`
plus `Config::to_models_manager_config()` so model metadata paths stop
depending on `core::Config`
- move login-owned/auth-owned code out of `core` into `codex-login`,
move model provider config into `codex-model-provider-info`, move API
bridge mapping into `codex-api`, move protocol-owned types/impls into
`codex-protocol`, and move response debug helpers into a dedicated
`response-debug-context` crate
- move feedback tag emission into `codex-feedback`, relocate tests to
the crates that now own the code, and keep broad temporary re-exports so
this PR avoids a giant import-only rewrite

## Major moves and decisions
- created `codex-models-manager` as the owner for model
cache/catalog/config/model info logic, including the new
`ModelsManagerConfig` struct
- created `codex-model-provider-info` as the owner for provider config
parsing/defaults and kept temporary `codex-login`/`codex-core`
re-exports for old import paths
- moved `api_bridge` error mapping + `CoreAuthProvider` into
`codex-api`, while `codex-login::api_bridge` temporarily re-exports
those symbols and keeps the `auth_provider_from_auth` wrapper
- moved `auth_env_telemetry` and `provider_auth` ownership to
`codex-login`
- moved `CodexErr` ownership to `codex-protocol::error`, plus
`StreamOutput`, `bytes_to_string_smart`, and network policy helpers to
protocol-owned modules
- created `codex-response-debug-context` for
`extract_response_debug_context`, `telemetry_transport_error_message`,
and related response-debug plumbing instead of leaving that behavior in
`core`
- moved `FeedbackRequestTags`, `emit_feedback_request_tags`, and
`emit_feedback_request_tags_with_auth_env` to `codex-feedback`
- deferred removal of temporary re-exports and the mechanical import
rewrites to a stacked follow-up PR so this PR stays reviewable

## Test moves
- moved auth refresh coverage from `core/tests/suite/auth_refresh.rs` to
`login/tests/suite/auth_refresh.rs`
- moved text encoding coverage from
`core/tests/suite/text_encoding_fix.rs` to
`protocol/src/exec_output_tests.rs`
- moved model info override coverage from
`core/tests/suite/model_info_overrides.rs` to
`models-manager/src/model_info_overrides_tests.rs`

---------

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

codex-rs/models-manager/src/model_info_overrides_tests.rs

@@ -0,0 +1,52 @@
+use codex_login::AuthManager;
+use codex_login::CodexAuth;
+
+use crate::ModelsManagerConfig;
+use crate::collaboration_mode_presets::CollaborationModesConfig;
+use crate::manager::ModelsManager;
+use codex_protocol::openai_models::TruncationPolicyConfig;
+use pretty_assertions::assert_eq;
+use tempfile::TempDir;
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn offline_model_info_without_tool_output_override() {
+    let codex_home = TempDir::new().expect("create temp dir");
+    let config = ModelsManagerConfig::default();
+    let auth_manager =
+        AuthManager::from_auth_for_testing(CodexAuth::create_dummy_chatgpt_auth_for_testing());
+    let manager = ModelsManager::new(
+        codex_home.path().to_path_buf(),
+        auth_manager,
+        /*model_catalog*/ None,
+        CollaborationModesConfig::default(),
+    );
+
+    let model_info = manager.get_model_info("gpt-5.1", &config).await;
+
+    assert_eq!(
+        model_info.truncation_policy,
+        TruncationPolicyConfig::bytes(/*limit*/ 10_000)
+    );
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn offline_model_info_with_tool_output_override() {
+    let codex_home = TempDir::new().expect("create temp dir");
+    let mut config = ModelsManagerConfig::default();
+    config.tool_output_token_limit = Some(123);
+    let auth_manager =
+        AuthManager::from_auth_for_testing(CodexAuth::create_dummy_chatgpt_auth_for_testing());
+    let manager = ModelsManager::new(
+        codex_home.path().to_path_buf(),
+        auth_manager,
+        /*model_catalog*/ None,
+        CollaborationModesConfig::default(),
+    );
+
+    let model_info = manager.get_model_info("gpt-5.1-codex", &config).await;
+
+    assert_eq!(
+        model_info.truncation_policy,
+        TruncationPolicyConfig::tokens(/*limit*/ 123)
+    );
+}