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/shared/files/nvim/lua/disabled/themes/dracula.lua

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