feat: migrate from lazy.nvim to vim.pack

Replace lazy.nvim plugin manager with Neovim 0.12's native vim.pack API.
All plugin config files rewritten from lazy.nvim spec tables to imperative
require/setup format with explicit vim.keymap.set() calls.

Key changes:
- vim.pack.add() with ~53 plugins in init.lua
- blink.cmp/pairs/download pinned to version tags (vim.version.range)
- PackChanged autocmd for markdown-preview build hook
- Ordered requires: colorscheme → ui → treesitter → completion → lsp → rest
- Plugin setup guards (gitsigns, which-key, blink.cmp) handle deferred
  plugin/ file loading correctly

Net reduction: ~438 lines across 13 files.

1 files changed, 54 insertions, 89 deletions

diff --git a/home/.config/nvim/lua/plugins/init.lua b/home/.config/nvim/lua/plugins/init.lua
index df8063e..8dce4cd 100644
--- a/home/.config/nvim/lua/plugins/init.lua
+++ b/home/.config/nvim/lua/plugins/init.lua
@@ -1,94 +1,59 @@
-return {
-  {
-    "iamcco/markdown-preview.nvim",
-    cmd = { "MarkdownPreviewToggle", "MarkdownPreview", "MarkdownPreviewStop" },
-    build = "cd app && yarn install",
-    ft = "markdown",
+require("tmux").setup({
+  resize = {
+    enable_default_keybindings = false,
   },
-  {
-    "aserowy/tmux.nvim",
-    event = "VeryLazy",
-    opts = {
-      resize = {
-        enable_default_keybindings = false,
-      },
-    },
+})
+
+require("which-key").setup({
+  spec = {
+    { "g", group = "[G]oto" },
+    { "yo", group = "Toggle options" },
+    { "]", group = "Navigate to next" },
+    { "[", group = "Navigate to previous" },
+    { "<leader>c", group = "[C]ode", mode = { "n", "x" } },
+    { "<leader>d", group = "[D]ocument" },
+    { "<leader>g", group = "[G]it" },
+    { "<leader>h", group = "Git [H]unk", mode = { "n", "v" } },
+    { "<leader>o", group = "[O]verseer" },
+    { "<leader>r", group = "[R]efactor" },
+    { "<leader>s", group = "[S]earch" },
+    { "<leader>w", group = "[W]orkspace" },
+    { "<leader>t", group = "[T]oggle" },
   },
-  {
-    "folke/which-key.nvim",
-    event = "VeryLazy",
-    opts = {
-      spec = {
-        { "g", group = "[G]oto" },
-        { "yo", group = "Toggle options" },
-        { "]", group = "Navigate to next" },
-        { "[", group = "Navigate to previous" },
-        { "<leader>c", group = "[C]ode", mode = { "n", "x" } },
-        { "<leader>d", group = "[D]ocument" },
-        { "<leader>g", group = "[G]it" },
-        { "<leader>h", group = "Git [H]unk", mode = { "n", "v" } },
-        { "<leader>o", group = "[O]verseer" },
-        { "<leader>r", group = "[R]efactor" },
-        { "<leader>s", group = "[S]earch" },
-        { "<leader>w", group = "[W]orkspace" },
-        { "<leader>t", group = "[T]oggle" },
-      },
-    },
-    keys = {
-      {
-        "<leader>?",
-        function()
-          require("which-key").show({ global = false })
-        end,
-        desc = "Buffer Local Keymaps (which-key)",
-      },
+})
+
+vim.keymap.set("n", "<leader>?", function()
+  require("which-key").show({ global = false })
+end, { desc = "Buffer Local Keymaps (which-key)" })
+
+require("quicker").setup({
+  keys = {
+    {
+      ">",
+      function()
+        require("quicker").expand({
+          before = 2,
+          after = 2,
+          add_to_existing = true,
+        })
+      end,
+      desc = "Expand quickfix context",
     },
-  },
-  {
-    "stevearc/quicker.nvim",
-    event = "FileType qf",
-    keys = {
-      {
-        "<leader>tq",
-        function()
-          require("quicker").toggle()
-        end,
-        desc = "[T]oggle [Q]uickfix",
-      },
-      {
-        "<leader>tl",
-        function()
-          require("quicker").toggle({ loclist = true })
-        end,
-        desc = "[T]oggle [L]oclist",
-      },
+    {
+      "<",
+      function()
+        require("quicker").collapse()
+      end,
+      desc = "Collapse quickfix context",
     },
-    opts = {
-      keys = {
-        {
-          ">",
-          function()
-            require("quicker").expand({
-              before = 2,
-              after = 2,
-              add_to_existing = true,
-            })
-          end,
-          desc = "Expand quickfix context",
-        },
-        {
-          "<",
-          function()
-            require("quicker").collapse()
-          end,
-          desc = "Collapse quickfix context",
-        },
-      },
-    },
-  },
-  {
-    "stevearc/oil.nvim",
-    opts = {},
-    lazy = false,
   },
-}
+})
+
+vim.keymap.set("n", "<leader>tq", function()
+  require("quicker").toggle()
+end, { desc = "[T]oggle [Q]uickfix" })
+vim.keymap.set("n", "<leader>tl", function()
+  require("quicker").toggle({ loclist = true })
+end, { desc = "[T]oggle [L]oclist" })
+
+require("oil").setup({})