fix(files): await pull-mode stream readiness

packages/shade-files/src/client/http-client.ts

@@ -444,8 +444,12 @@ export function createFilesHttpClient(
         };
         return out;
       }
-      // Streamed read — only supported when the queue drainer is wired.
-      if (drainer === null) {
+      // Streamed read — only supported when pull-mode was configured.
+      // `drainer` is assigned asynchronously after the streams bridge has
+      // subscribed, so checking it here races client construction. The
+      // promise itself is the synchronous configuration signal; awaiting it
+      // also guarantees the drainer has been installed by its `.then()`.
+      if (streamsBridgePromise === null) {
         throw new InternalFileError(
           `http RPC client received a streamed read (size ${wire.size}) but is in inline-only mode. Pass { outboundQueueUrl, transferBaseUrl } when constructing the client to enable streamed reads.`,
         );
@@ -507,8 +511,11 @@ export function createFilesHttpClient(
         );
       }
 
-      // Streamed write — requires the queue drainer + streams-bridge.
-      if (drainer === null) {
+      // Streamed write — requires pull-mode configuration. Do not inspect
+      // `drainer` as a readiness flag: bridge registration is asynchronous,
+      // and an immediate large write must wait for it instead of being
+      // misclassified as an inline-only client.
+      if (streamsBridgePromise === null) {
         throw new ConflictError(
           `http RPC client supports inline writes only (≤ ${INLINE_THRESHOLD} bytes). The supplied input was promoted to streams (size ${decision.size ?? 'unknown'}). Pass { outboundQueueUrl, transferBaseUrl } to enable streamed writes.`,
         );