feat: VSCode 风格 Neovim 配置

- 分层架构：config/{options,keymaps,lazy} + plugins/
- 保留：blink.cmp, oil.nvim, runner.lua, cmake-tools, diffview, tokyonight
- 新增 UI：bufferline, lualine, noice, nvim-notify, dashboard, dressing
- 新增编辑器：Comment, nvim-surround, vim-illuminate, toggleterm, flash
- 新增视觉：indent-blankline, nvim-ufo, rainbow-delimiters
- 新增 Git：lazygit 集成
- 新增 DAP：persistent-breakpoints, nvim-dap-virtual-text
- 修复：which-key 启用, rustaceanvim 填充, 键位冲突解决
- 语法检查：22/22 文件全部通过 luajit -b

lua/plugins/oil.lua

@@ -0,0 +1,37 @@
+-- =============================================================================
+-- oil.lua — 文件浏览器
+-- =============================================================================
+-- 【保留】你的完整 oil.nvim 配置。
+-- 【无修改】oil 作为默认文件浏览器不变。
+
+return {
+  {
+    "stevearc/oil.nvim",
+    dependencies = {
+      "nvim-tree/nvim-web-devicons",
+    },
+    opts = {
+      default_file_explorer = true,
+      keymaps = {
+        ["<CR>"]  = "actions.select",
+        ["<C-p>"] = "actions.preview",
+        ["<C-c>"] = "actions.close",
+        ["<C-r>"] = "actions.refresh",
+        ["<C-h>"] = "actions.toggle_hidden",
+        ["g?"]    = "actions.show_help",
+      },
+      view_options = {
+        show_hidden = true,
+      },
+      float = {
+        padding    = 2,
+        max_width  = 90,
+        border     = "rounded",
+      },
+    },
+    keys = {
+      { "-",          "<cmd>Oil<cr>", desc = "打开父目录" },
+      { "<leader>fe", "<cmd>Oil<cr>", desc = "文件浏览器" },
+    },
+  },
+}