[datlechin]

Summary

• A connection's first catalog puts the sidebar outline up in a later run loop turn than the one it landed in (CommittedTurn.after: the frame's transaction commits, then a main-queue hop). On 50,000 MySQL tables the listing could land while the restored query tab's frame was committing, and the outline's build joined that turn: one stall of about 180 ms where each part alone is under 100. The loading state stays up until then, so no frame shows a half-built sidebar.
• baseline.json is recorded again on the Mac it names. perf(sidebar): cut connect and filter stalls on large catalogs #3842 moved the end of sidebar-listing to after the outline's frame, and perf(connection-window): keep the restored tab out of the connected panes' frame #3846 gave the footprint a budget, so the old budgets measured something else and the footprint had none.

Test plan

• New: SidebarObjectListPresentationTests.heldCatalogReadsAsLoading, NSWindowNextFrameTests.committedTurnRunsLater.
• Local: sidebar presentation, reconcile, schema filter, chrome and frame suites pass; lint clean.

Refs #3661