Add auth env observability (#14905)

CXC-410 Emit Env Var Status with `/feedback` report

Add more observability on top of #14611 

[Unset](https://openai.sentry.io/issues/7340419168/?project=4510195390611458&query=019cfa8d-c1ba-7002-96fa-e35fc340551d&referrer=issue-stream)

[Set](https://openai.sentry.io/issues/7340426331/?project=4510195390611458&query=019cfa91-aba1-7823-ab7e-762edfbc0ed4&referrer=issue-stream)
<img width="1063" height="610" alt="image"
src="https://github.com/user-attachments/assets/937ab026-1c2d-4757-81d5-5f31b853113e"
/>


###### Summary
- Adds auth-env telemetry that records whether key auth-related env
overrides were present on session start and request paths.
- Threads those auth-env fields through `/responses`, websocket, and
`/models` telemetry and feedback metadata.
- Buckets custom provider `env_key` configuration to a safe
`"configured"` value instead of emitting raw config text.
- Keeps the slice observability-only: no raw token values or raw URLs
are emitted.

###### Rationale (from spec findings)
- 401 and auth-path debugging needs a way to distinguish env-driven auth
paths from sessions with no auth env override.
- Startup and model-refresh failures need the same auth-env diagnostics
as normal request failures.
- Feedback and Sentry tags need the same auth-env signal as OTel events
so reports can be triaged consistently.
- Custom provider config is user-controlled text, so the telemetry
contract must stay presence-only / bucketed.

###### Scope
- Adds a small `AuthEnvTelemetry` bundle for env presence collection and
threads it through the main request/session telemetry paths.
- Does not add endpoint/base-url/provider-header/geo routing attribution
or broader telemetry API redesign.

###### Trade-offs
- `provider_env_key_name` is bucketed to `"configured"` instead of
preserving the literal configured env var name.
- `/models` is included because startup/model-refresh auth failures need
the same diagnostics, but broader parity work remains out of scope.
- This slice keeps the existing telemetry APIs and layers auth-env
fields onto them rather than redesigning the metadata model.

###### Client follow-up
- Add the separate endpoint/base-url attribution slice if routing-source
diagnosis is still needed.
- Add provider-header or residency attribution only if auth-env presence
proves insufficient in real reports.
- Revisit whether any additional auth-related env inputs need safe
bucketing after more 401 triage data.

###### Testing
- `cargo test -p codex-core emit_feedback_request_tags -- --nocapture`
- `cargo test -p codex-core
collect_auth_env_telemetry_buckets_provider_env_key_name -- --nocapture`
- `cargo test -p codex-core
models_request_telemetry_emits_auth_env_feedback_tags_on_failure --
--nocapture`
- `cargo test -p codex-otel
otel_export_routing_policy_routes_api_request_auth_observability --
--nocapture`
- `cargo test -p codex-otel
otel_export_routing_policy_routes_websocket_connect_auth_observability
-- --nocapture`
- `cargo test -p codex-otel
otel_export_routing_policy_routes_websocket_request_transport_observability
-- --nocapture`
- `cargo test -p codex-core --no-run --message-format short`
- `cargo test -p codex-otel --no-run --message-format short`

---------

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

codex-rs/core/src/codex.rs

@@ -17,6 +17,7 @@ use crate::analytics_client::AppInvocation;
 use crate::analytics_client::InvocationType;
 use crate::analytics_client::build_track_events_context;
 use crate::apps::render_apps_section;
+use crate::auth_env_telemetry::collect_auth_env_telemetry;
 use crate::commit_attribution::commit_message_trailer_instruction;
 use crate::compact;
 use crate::compact::InitialContextInjection;
@@ -1565,6 +1566,10 @@ impl Session {
         let originator = crate::default_client::originator().value;
         let terminal_type = terminal::user_agent();
         let session_model = session_configuration.collaboration_mode.model().to_string();
+        let auth_env_telemetry = collect_auth_env_telemetry(
+            &session_configuration.provider,
+            auth_manager.codex_api_key_env_enabled(),
+        );
         let mut session_telemetry = SessionTelemetry::new(
             conversation_id,
             session_model.as_str(),
@@ -1576,7 +1581,8 @@ impl Session {
             config.otel.log_user_prompt,
             terminal_type.clone(),
             session_configuration.session_source.clone(),
-        );
+        )
+        .with_auth_env(auth_env_telemetry.to_otel_metadata());
         if let Some(service_name) = session_configuration.metrics_service_name.as_deref() {
             session_telemetry = session_telemetry.with_metrics_service_name(service_name);
         }