refactor: add TypeScript type annotations to fix implicit 'any' errors

Fixed 12 type errors by adding proper type annotations:

Quick Wins Completed:
- do_on_key.js: Added JSDoc types for KeyboardEvent and function parameters
- randomize.js: Added JSDoc types with generic template for array shuffling
- cookie.js: Added JSDoc types for Request API
- stripHtmlTags.ts: Added TypeScript types for string parameter

Progress: 12/1239 errors fixed (Quick Wins - Category 1 partial)

Created TODO_cleanup.md to track remaining 1227 type errors systematically.

src/lib/components/do_on_key.js

@@ -1,3 +1,9 @@
+/**
+ * @param {KeyboardEvent} event
+ * @param {string} key
+ * @param {boolean} needsctrl
+ * @param {() => void} fn
+ */
 export function do_on_key(event, key, needsctrl, fn){
 	if(event.key == key){
 		if(needsctrl && !event.ctrlKey){