docs: move todos.txt into web/ (single repo, single branch)

todos.txt

@@ -0,0 +1,5 @@
+i want only one git repo and one branch and push only to hf spaces. that's all.
+
+3. Make Gemini 2.5 Pro optimize UI/UX, moderne UIs
+   3.1 for desktop
+   3.2 for tablet /smarphone