Explain CLI case-sensitivity probe isolation

src/apps/cli/services/storageCaseSensitivity.ts

@@ -1,6 +1,8 @@
 import { fs, path } from "@vrtmrz/livesync-commonlib/node";
 
 export function isStorageCaseInsensitive(vaultPath: string): boolean {
+    // Probe with an empty directory on the Vault filesystem. The dot-prefixed name is
+    // excluded by the CLI watcher and synchronisation filters; finally removes it after detection.
     const probePath = fs.mkdtempSync(path.join(vaultPath, ".livesync-case-"));
     try {
         const original = fs.statSync(probePath);