PR #214 adds transfer, persistence, event routing, and watcher ownership to already large MarkdownViewer.svelte and src-tauri/src/lib.rs. Extract focused frontend session lifecycle and Rust window-runtime modules while preserving current behavior.\n\nThis is intentionally follow-up work: several related multi-window PRs remain in flight, so coordinate the extraction after their merge order stabilizes.
PR #214 adds transfer, persistence, event routing, and watcher ownership to already large
MarkdownViewer.svelteandsrc-tauri/src/lib.rs. Extract focused frontend session lifecycle and Rust window-runtime modules while preserving current behavior.\n\nThis is intentionally follow-up work: several related multi-window PRs remain in flight, so coordinate the extraction after their merge order stabilizes.