Track credential storage outcomes and redact sensitive errors (#49384)

## Why

Successful file fallback can hide a secure-store failure. Storage diagnostics need to distinguish that fallback from explicit file storage while keeping credential values out of error output.

## What changed

- Record credential load, save, delete, and fallback-file cleanup outcomes, including secure-store failures and fallback reasons.
- Preserve the initiating client's attribution across app-server requests, login tasks, sessions, turns, and blocking token persistence.
- Preserve storage error context and typed causes while redacting credential JSON data errors and payload-bearing keyring errors.
- Include sanitized fallback completion warnings in the default `codex login` file logs.

## Testing

Add coverage for storage policy and metric attribution, credential redaction, login diagnostics, concurrent app-server clients, device-code login, and token refresh during a turn.

GitOrigin-RevId: 6d5651c1718d184016fa77befa02aa528750b2ae

codex-rs/cli/tests/daemon_telemetry.rs

@@ -53,8 +53,14 @@ async fn foreground_update_respects_consent_and_reports_unconfirmed() -> anyhow:
             continue;
         }
         let body: Value = serde_json::from_slice(&requests[0].body)?;
-        let metric = &body["resourceMetrics"][0]["scopeMetrics"][0]["metrics"][0];
-        assert_eq!(metric["name"], "codex.daemon.update");
+        let metric = body["resourceMetrics"]
+            .as_array()
+            .into_iter()
+            .flatten()
+            .flat_map(|resource| resource["scopeMetrics"].as_array().into_iter().flatten())
+            .flat_map(|scope| scope["metrics"].as_array().into_iter().flatten())
+            .find(|metric| metric["name"] == "codex.daemon.update")
+            .context("daemon update metric")?;
         assert!(
             metric["sum"]["dataPoints"][0]["attributes"]
                 .as_array()