Preserve usage limit windows in turn and compaction analytics (#48174)

## Why

Usage limit errors discarded the server-selected window responsible for the limit, leaving turn and compaction analytics unable to distinguish five-hour limits from weekly limits.

## What changed

Preserve optional `limit_window_minutes` from usage limit error responses in `UsageLimitReachedError` and report it as `usage_limit_window_minutes` in turn and compaction events. Accept unsigned integers that fit in `u16`; treat missing, null, malformed, or out-of-range values as unknown. Events for other error kinds report `null`.

## Testing

Add coverage for HTTP and wrapped WebSocket error mapping, analytics serialization and reduction, and app-server propagation to turn and local/remote compaction events. Cases include five-hour and weekly windows, missing or invalid values, and unrelated errors.

GitOrigin-RevId: a32066a007559d91a3c868a756bfd0f976777176

codex-rs/codex-api/src/api_bridge_tests.rs

@@ -457,6 +457,48 @@ fn map_api_error_distinguishes_http_quota_errors_from_rate_limits() {
     }
 }
 
+#[test]
+fn map_api_error_preserves_optional_usage_limit_window() {
+    let cases = [
+        (None, None),
+        (Some(serde_json::json!(null)), None),
+        (Some(serde_json::json!(300)), Some(300)),
+        (Some(serde_json::json!(10080)), Some(10080)),
+        (Some(serde_json::json!(-1)), None),
+        (Some(serde_json::json!(65536)), None),
+        (Some(serde_json::json!("300")), None),
+        (Some(serde_json::json!({"minutes": 300})), None),
+    ];
+
+    for (window, expected) in cases {
+        let mut body = serde_json::json!({
+            "error": {
+                "type": "usage_limit_reached",
+                "plan_type": "pro",
+            }
+        });
+        if let Some(window) = window.as_ref() {
+            body["error"]["limit_window_minutes"] = window.clone();
+        }
+        let err = map_api_error(ApiError::Transport(TransportError::Http {
+            retry_after: None,
+            status: http::StatusCode::TOO_MANY_REQUESTS,
+            url: None,
+            headers: None,
+            body: Some(body.to_string()),
+        }));
+
+        let CodexErrorDetails::UsageLimitReached(usage_limit) = err.details() else {
+            panic!("expected usage-limit error for {window:?}, got {err:?}");
+        };
+        assert_eq!(usage_limit.limit_window_minutes, expected, "{window:?}");
+        assert_eq!(
+            err.to_codex_protocol_error(),
+            CodexErrorInfo::UsageLimitExceeded
+        );
+    }
+}
+
 #[test]
 fn map_api_error_maps_usage_limit_limit_name_header() {
     let mut headers = HeaderMap::new();