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/core/tests/suite/client.rs

@@ -1,3 +1,4 @@
+use crate::error::CodexErr;
 use codex_core::ModelClient;
 use codex_core::ModelProviderInfo;
 use codex_core::NewThread;
@@ -6,7 +7,6 @@ use codex_core::ResponseEvent;
 use codex_core::ThreadManager;
 use codex_core::WireApi;
 use codex_core::built_in_model_providers;
-use codex_core::error::CodexErr;
 use codex_core::models_manager::collaboration_mode_presets::CollaborationModesConfig;
 use codex_features::Feature;
 use codex_login::AuthCredentialsStoreMode;
@@ -34,7 +34,6 @@ use codex_protocol::models::ReasoningItemContent;
 use codex_protocol::models::ReasoningItemReasoningSummary;
 use codex_protocol::models::ResponseItem;
 use codex_protocol::models::WebSearchAction;
-use codex_protocol::openai_models::ModelsResponse;
 use codex_protocol::openai_models::ReasoningEffort;
 use codex_protocol::protocol::EventMsg;
 use codex_protocol::protocol::Op;
@@ -1636,8 +1635,8 @@ async fn user_turn_explicit_reasoning_summary_overrides_model_catalog_default()
     )
     .await;
 
-    let mut model_catalog: ModelsResponse =
-        serde_json::from_str(include_str!("../../models.json")).expect("valid models.json");
+    let mut model_catalog = codex_models_manager::bundled_models_response()
+        .unwrap_or_else(|err| panic!("bundled models.json should parse: {err}"));
     let model = model_catalog
         .models
         .iter_mut()
@@ -1749,8 +1748,8 @@ async fn reasoning_summary_none_overrides_model_catalog_default() -> anyhow::Res
     )
     .await;
 
-    let mut model_catalog: ModelsResponse =
-        serde_json::from_str(include_str!("../../models.json")).expect("valid models.json");
+    let mut model_catalog = codex_models_manager::bundled_models_response()
+        .unwrap_or_else(|err| panic!("bundled models.json should parse: {err}"));
     let model = model_catalog
         .models
         .iter_mut()