fix(sync): don't route the remote-http persistent transcript dir through cleanup (#1802)

The ingest finally ran cleanupStagingDir() unconditionally, but in remote-http
mode stagingDir is the PERSISTENT transcript dir (~/.gstack/transcripts/) that
gstack-brain-sync push must consume. The remote-http branch documents the intent
to skip cleanup, but a finally runs on its return. Gate the call on
!remoteHttpMode so the ownership guard only ever sees .staging-ingest-* dirs.
Pre-gate this dir was deleted outright (broken artifacts handoff); post-#1827 it
produced a false 'prevent data loss' warning every sync.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

bin/gstack-memory-ingest.ts

@@ -1778,7 +1778,15 @@ async function ingestPass(args: CliArgs): Promise<BulkResult> {
       );
     }
   } finally {
-    cleanupStagingDir(stagingDir);
+    // #1802 D1: in remote-http mode `stagingDir` is the PERSISTENT transcript
+    // dir (makePersistentTranscriptDir, under ~/.gstack/transcripts/) that
+    // gstack-brain-sync push must pick up — it is NOT a `.staging-ingest-*` dir
+    // and must never be deleted here. The remote-http branch above already
+    // documents this intent ("Skip the ... cleanupStagingDir paths"), but a
+    // `finally` runs on its `return`, so the gate has to live here. Gating on
+    // mode (rather than widening the ownership guard) keeps checkOwnedStagingDir
+    // strict: it only ever sees `.staging-ingest-*` dirs.
+    if (!remoteHttpMode) cleanupStagingDir(stagingDir);
     _activeStagingDir = null;
   }