refactor(lua): reformat and clean up Lua configuration files

lua/plugins/mason.lua

@@ -0,0 +1,34 @@
+-- Customize Mason
+-- This file configures non-LSP tools (formatters, linters, debuggers, etc.)
+-- LSP servers are configured in astrolsp.lua via mason-lspconfig
+
+---@type LazySpec
+return {
+  -- use mason-tool-installer for automatically installing Mason packages
+  {
+    "WhoIsSethDaniel/mason-tool-installer.nvim",
+    -- overrides `require("mason-tool-installer").setup(...)`
+    opts = {
+      -- Make sure to use the names found in `:Mason`
+      ensure_installed = {
+        -- Formatters (non-LSP)
+        "stylua",
+        "rustfmt",
+        "taplo",
+
+        -- Linters
+        "stylelint",
+        "markdownlint",
+
+        -- Debuggers
+        "debugpy",
+
+        -- Other tools
+        "tree-sitter-cli",
+
+        -- Note: oxlint and oxfmt should be installed separately via cargo/npm
+        -- Note: LSP servers are configured in astrolsp.lua
+      },
+    },
+  },
+}