refactor: remove dead code

Delete unused components, hooks and utilities that have no remaining references, and drop their now-unused exports (augmentations/string, Number.prototype.hoursToMilliseconds). Also drop the dangling ExampleGlobalModalUsage reference from GLOBAL_MODAL_GUIDE.md.

augmentations/index.ts

@@ -1,4 +1,3 @@
 export * from "./api";
 export * from "./mmkv";
 export * from "./number";
-export * from "./string";