chore: import upstream snapshot with attribution

apps/sim/lib/copilot/request/go/fetch.ts

@@ -0,0 +1,112 @@
+import { type Context, context, SpanStatusCode, trace } from '@opentelemetry/api'
+import { CopilotLeg } from '@/lib/copilot/generated/trace-attribute-values-v1'
+import { TraceAttr } from '@/lib/copilot/generated/trace-attributes-v1'
+import { traceHeaders } from '@/lib/copilot/request/go/propagation'
+import { isActionableErrorStatus, markSpanForError } from '@/lib/copilot/request/otel'
+
+// Lazy tracer resolution: module-level `trace.getTracer()` can be evaluated
+// before `instrumentation-node.ts` installs the TracerProvider under
+// Next.js 16 + Turbopack dev, freezing a NoOp tracer and silently dropping
+// every outbound Sim → Go span. Resolving per-call avoids the race.
+const getTracer = () => trace.getTracer('sim-copilot-http', '1.0.0')
+
+interface OutboundFetchOptions extends RequestInit {
+  otelContext?: Context
+  spanName?: string
+  operation?: string
+  attributes?: Record<string, string | number | boolean>
+}
+
+/**
+ * Perform an outbound Sim → Go fetch wrapped in an OTel child span so each
+ * call shows up as a distinct segment in Jaeger, and propagates the W3C
+ * traceparent so the Go-side span joins the same trace.
+ *
+ * The span captures generic attributes (method, status, duration, response
+ * size, error code) so any future latency investigation — not just images or
+ * Bedrock — has uniform metadata to work with.
+ */
+export async function fetchGo(url: string, options: OutboundFetchOptions = {}): Promise<Response> {
+  const {
+    otelContext,
+    spanName,
+    operation,
+    attributes,
+    headers: providedHeaders,
+    ...init
+  } = options
+
+  const parsed = safeParseUrl(url)
+  const pathname = parsed?.pathname ?? url
+  const method = (init.method ?? 'GET').toUpperCase()
+  const parentContext = otelContext ?? context.active()
+
+  const span = getTracer().startSpan(
+    spanName ?? `sim → go ${pathname}`,
+    {
+      attributes: {
+        [TraceAttr.HttpMethod]: method,
+        [TraceAttr.HttpUrl]: url,
+        [TraceAttr.HttpTarget]: pathname,
+        [TraceAttr.NetPeerName]: parsed?.host ?? '',
+        [TraceAttr.CopilotLeg]: CopilotLeg.SimToGo,
+        ...(operation ? { [TraceAttr.CopilotOperation]: operation } : {}),
+        ...(attributes ?? {}),
+      },
+    },
+    parentContext
+  )
+
+  const activeContext = trace.setSpan(parentContext, span)
+  const propagatedHeaders = traceHeaders({}, activeContext)
+  const mergedHeaders = {
+    ...(providedHeaders as Record<string, string> | undefined),
+    ...propagatedHeaders,
+  }
+
+  const start = performance.now()
+  try {
+    const response = await context.with(activeContext, () =>
+      fetch(url, {
+        ...init,
+        method,
+        headers: mergedHeaders,
+      })
+    )
+    const elapsedMs = performance.now() - start
+    const contentLength = Number(response.headers.get('content-length') ?? 0)
+    span.setAttribute(TraceAttr.HttpStatusCode, response.status)
+    span.setAttribute(TraceAttr.HttpResponseHeadersMs, Math.round(elapsedMs))
+    if (contentLength > 0) {
+      span.setAttribute(TraceAttr.HttpResponseContentLength, contentLength)
+    }
+    // Only mark ERROR for actionable status codes. 4xx that represent
+    // normal auth/validation rejections (400/401/403/404/405/422/etc.)
+    // stay UNSET so error dashboards don't drown in expected rejection
+    // paths. See `isActionableErrorStatus` in Go's telemetry middleware
+    // for the mirror rule (5xx + 402/409/429).
+    if (isActionableErrorStatus(response.status)) {
+      span.setStatus({
+        code: SpanStatusCode.ERROR,
+        message: `HTTP ${response.status}`,
+      })
+    } else {
+      span.setStatus({ code: SpanStatusCode.OK })
+    }
+    return response
+  } catch (error) {
+    span.setAttribute(TraceAttr.HttpResponseHeadersMs, Math.round(performance.now() - start))
+    markSpanForError(span, error)
+    throw error
+  } finally {
+    span.end()
+  }
+}
+
+function safeParseUrl(url: string): URL | null {
+  try {
+    return new URL(url)
+  } catch {
+    return null
+  }
+}