Restructure modules/shared and update all imports

- Delete 2024-12-rework/ folder
- Rename modules/hosts/common to modules/shared, then split into:
  - modules/shared/home/general
  - modules/shared/home/linux
  - modules/shared/nixos
- Update all import paths throughout the codebase
- Update lib/*.nix to use new paths
- Fix hardcoded /Users/${username} to use config.home.homeDirectory
- Update README and examples/flake-structure.nix

modules/shared/files/nvim/lua/plugins/treesitter.lua

@@ -0,0 +1,53 @@
+return {
+  "nvim-treesitter/nvim-treesitter",
+  build = ":TSUpdate",
+  config = function()
+    local config = require("nvim-treesitter.configs")
+    config.setup({
+      auto_install = true,
+      highlight = { enable = true },
+      indent = { enable = true },
+      sync_install = false,
+      ensure_installed = {
+        "bash",
+        "css",
+        "csv",
+        "diff",
+        "dockerfile",
+        "git_config",
+        "git_rebase",
+        "gitattributes",
+        "gitignore",
+        "go",
+        "hcl",
+        "hocon",
+        "html",
+        "javascript",
+        "json",
+        "lua",
+        "make",
+        "markdown",
+        "markdown_inline",
+        "nix",
+        "passwd",
+        "promql",
+        "puppet",
+        "python",
+        "regex",
+        --"pip_requirements",
+        "ruby",
+        "sql",
+        "ssh_config",
+        "terraform",
+        "toml",
+        "tsv",
+        "typescript",
+        "udev",
+        "vim",
+        "vimdoc",
+        "xml",
+        "yaml",
+      },
+    })
+  end,
+}