perf: files-screen visibleEntries memo recomputes on every keystroke, no debounce

[Interstellar-code]

File: src/screens/files/files-screen.tsx:1517-1542

visibleEntries is a useMemo over the full file tree, keyed on treeQuery (raw search input). It re-walks the tree on every keystroke.

Suggested fix: debounce treeQuery (150-200ms) before feeding it to the memo.

Related: entryCounts (line 1543) also walks the tree recursively on every entries change — consider caching on entries reference equality.

Severity: medium — feels janky on bigger trees.

[Interstellar-code]

Fixed in 1413277: added debouncedTreeQuery (150ms) — visibleEntries memo is now keyed on the debounced value; immediate treeQuery still feeds the input + visual hints.