Restructure modules/shared and update all imports

- Rename modules/hosts/common to modules/shared
- Split shared into home/general, home/linux, and nixos subdirectories
- Update all import paths in lib/ and modules/hosts/
- Fix hardcoded /Users/ path to use config.home.homeDirectory
- Update .sops.yaml path for secrets

modules/hosts/common/files/nvim/lua/disabled/cheatsheet.lua

@@ -1,9 +0,0 @@
-return {
-  "sudormrfbin/cheatsheet.nvim",
-  dependencies = {
-    'nvim-telescope/telescope.nvim',
-    'nvim-lua/popup.nvim',
-    'nvim-lua/plenary.nvim',
-  },
-  config = true,
-}