fix(files): prevent autosave data loss on load lag and binary files

Guard FilesView autosave until the selected file has finished loading,
refuse binary/PDF/office/archive text saves, and add a persisted global
autoSaveEnabled setting (default true) under Settings → General.

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

packages/ui/src/components/sections/openchamber/OpenChamberPage.tsx

@@ -146,6 +146,7 @@ const GeneralSectionContent: React.FC = () => {
             {!isVSCode && <OpenCodeCliSettings />}
             <OpenChamberVisualSettings visibleSettings={[
                 'fileEditorKeymap',
+                'autoSaveEnabled',
                 'expandedEditorToolbar',
                 ...(!isVSCode ? ['terminalQuickKeys' as const] : []),
                 ...(!isVSCode ? ['terminalShell' as const] : []),