fix(storage): adapt timestamp guard to current Commonlib

Use the packaged Commonlib type import and add regression coverage for every Obsidian vault and storage write method. Verify that fractional timestamps are floored without mutating caller-owned options.

src/serviceModules/FileSystemAdapters/sanitizeWriteOptions.ts

@@ -1,4 +1,4 @@
-import type { UXDataWriteOptions } from "@lib/common/types";
+import type { UXDataWriteOptions } from "@vrtmrz/livesync-commonlib/compat/common/types";
 
 /**
  * Coerce the timestamp fields of a write-options object to integer milliseconds.