Use the LazyVim oxc extra instead of hand-rolled oxlint config

The oxlint LSP now enables type-aware linting on its own when tsgolint is
present and .oxlintrc.json mentions typescript, and ships :LspOxlintFixAll --
which is what the oxlint_fix function reimplemented by shelling out to the CLI.
The extra also sets fixKind = "all" and prefers the top-level oxlint config in
monorepos. Fixes now apply as a workspace edit instead of writing to disk and
reloading.

oxfmt takes js/ts/json/vue over prettier; prettier keeps css/html/yaml/markdown.
Add oxlint to mason so it resolves outside projects with a local install.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

lua/plugins/conform.lua

@@ -0,0 +1,24 @@
+local oxfmt_owned = {
+  "javascript",
+  "javascriptreact",
+  "typescript",
+  "typescriptreact",
+  "json",
+  "jsonc",
+  "vue",
+}
+
+return {
+  "stevearc/conform.nvim",
+  opts = function(_, opts)
+    opts.formatters_by_ft = opts.formatters_by_ft or {}
+    for _, ft in ipairs(oxfmt_owned) do
+      local formatters = opts.formatters_by_ft[ft]
+      if formatters then
+        opts.formatters_by_ft[ft] = vim.tbl_filter(function(formatter)
+          return formatter ~= "prettier"
+        end, formatters)
+      end
+    end
+  end,
+}