[tiensonqin]

Closed drawers currently mount their hidden sidebar, including its NavigationStack, and the SwiftUI QuickLook preview modifier eagerly links the file-preview framework before any preview request. Both add work before the first content frame.

Keep compact drawer panels unmounted until their first reveal, then retain them across closes. Use UIKit's native document preview on iOS so QuickLook loads when a file is opened; keep the existing macOS preview. Handle dismissal during presentation and suppress duplicate wire dismiss events.

On the same iOS 26 simulator with the same isolated Lambda Journals fixture, five fresh-process Release runs reduced pre-main median from 383ms to 276ms with demand-loaded previews. Deferring the closed drawer reduced view creation median from 217ms to 174ms. These are simulator/local-renderer measurements, not a claim that the full app has reached its 300ms launch target.

Validation:

• Native simulator checks verify QuickLook is absent before a request, PDF preview opens/closes/reopens correctly, native dismissal emits once, and retained wire nodes do not reopen.
• Native drawer checks verify closed panels stay unmounted, first reveal uses current data, initially open panels render, and reopen preserves state.
• The mobile 300-row drawer harness passes six transitions without rebuilding content or losing scroll identity/offset; initially open and regular-width cases pass.
• Release iOS and macOS backend builds pass; the consuming mobile app's 104 Swift UI tests pass.

Run the standalone checks with the commands in platform/apple/Tests/RuntimeChecks/README.md. No XCTest invocation is required.

Based directly on freshly fetched main (9a8de61).