fix(client): a seek's first segments are held while it lands, not dropped

They are the new stream, header first. Dropped, a cast relay restarted at the
landing got no ftyp/moov and the receiver gave up; they are now replayed in
order once reinitAt/resumeAt is done.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/packages/meshbay-hub/tests/harness/window_leak.mjs b/packages/meshbay-hub/tests/harness/window_leak.mjs
index d5185de..f05d8c0 100644
--- a/packages/meshbay-hub/tests/harness/window_leak.mjs
+++ b/packages/meshbay-hub/tests/harness/window_leak.mjs
@@ -41,20 +41,23 @@ let cancelled = false;
 const pump = () => {};
 const flushQueue = () => {};
 const gekRef = { current: null };
+// Not holding: these are the abandoned stream's segments, before any stream_init.
+const heldRef = { current: null };
+const consumeSegment = async () => {};
 const window_ = { MeshBayCrypto: { decryptChunkBin: async () => new Uint8Array(4) } };
 
 const silentConsole = { log() {}, warn() {}, error() {} };
 
 const handler = new Function(
   'msg', 'cancelled', 'awaitingInitRef', 'outstandingRef', 'queueRef',
-  'entry', 'gekRef', 'pump', 'flushQueue', 'console', 'window',
+  'entry', 'gekRef', 'pump', 'flushQueue', 'console', 'window', 'heldRef', 'consumeSegment',
   `return (async () => {${source}})();`);
 
 const deliver = (n) => Promise.all(
   Array.from({ length: n }, (_, i) => handler(
     { file_id: entry.id, segment_index: i, nonce: 'n', ct: 'c' },
     cancelled, awaitingInitRef, outstandingRef, queueRef, entry, gekRef,
-    pump, flushQueue, silentConsole, window_)));
+    pump, flushQueue, silentConsole, window_, heldRef, consumeSegment)));
 
 const run = async () => {
   // The whole window arrives while reinitAt is still awaiting its updateends.