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/themes/kanagawa.lua

@@ -1,8 +0,0 @@
-return {
-  "rebelot/kanagawa.nvim",
-  lazy = false,
-  priority = 1000,
-  config = function()
-    vim.cmd.colorscheme "kanagawa"
-  end,
-}