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, 67 insertions, 93 deletions

diff --git a/home/.config/nvim/lua/plugins/debug.lua b/home/.config/nvim/lua/plugins/debug.lua
index b47dd63..bef0d1c 100644
--- a/home/.config/nvim/lua/plugins/debug.lua
+++ b/home/.config/nvim/lua/plugins/debug.lua
@@ -1,101 +1,75 @@
-return {
-  {
-    "miroshQa/debugmaster.nvim",
-    branch = "dashboard",
-    dependencies = "mfussenegger/nvim-dap",
-    keys = {
-      {
-        "<leader>td",
-        function()
-          require("debugmaster").mode.toggle()
-        end,
-        desc = "[T]oggle [D]ebug mode",
-      },
-    },
-  },
-  {
-    "mfussenegger/nvim-dap",
-    config = function()
-      local dap = require("dap")
+vim.keymap.set("n", "<leader>td", function()
+  require("debugmaster").mode.toggle()
+end, { desc = "[T]oggle [D]ebug mode" })
 
-      local function get_env_vars()
-        local variables = vim.fn.environ()
-        table.insert(variables, { ASAN_OPTIONS = "detect_leaks=0" })
-        return variables
-      end
+local dap = require("dap")
 
-      dap.adapters.lldb = {
-        type = "executable",
-        command = "lldb-dap",
-        name = "lldb",
-        env = get_env_vars,
-      }
-      dap.adapters.gdb = {
-        type = "executable",
-        command = "gdb",
-        args = { "--interpreter=dap" },
-        env = get_env_vars,
-      }
-      dap.adapters.codelldb = {
-        type = "executable",
-        command = "codelldb",
-        env = get_env_vars,
-      }
+local function get_env_vars()
+  local variables = vim.fn.environ()
+  table.insert(variables, { ASAN_OPTIONS = "detect_leaks=0" })
+  return variables
+end
 
-      local function get_program()
-        local _program
-        vim.ui.input({
-          prompt = "Program: ",
-          complete = "file_in_path",
-        }, function(res)
-          _program = res
-        end)
-        return vim.fn.system("which " .. _program):gsub("\n$", "")
-      end
+dap.adapters.lldb = {
+  type = "executable",
+  command = "lldb-dap",
+  name = "lldb",
+  env = get_env_vars,
+}
+dap.adapters.gdb = {
+  type = "executable",
+  command = "gdb",
+  args = { "--interpreter=dap" },
+  env = get_env_vars,
+}
+dap.adapters.codelldb = {
+  type = "executable",
+  command = "codelldb",
+  env = get_env_vars,
+}
 
-      local function get_args()
-        local _args
-        vim.ui.input({
-          prompt = "Args: ",
-          default = vim.fn.getreg("+"),
-          complete = "file",
-        }, function(res)
-          _args = res
-        end)
-        return require("dap.utils").splitstr(_args)
-      end
+local function get_program()
+  local _program
+  vim.ui.input({
+    prompt = "Program: ",
+    complete = "file_in_path",
+  }, function(res)
+    _program = res
+  end)
+  return vim.fn.system("which " .. _program):gsub("\n$", "")
+end
 
-      dap.configurations.cpp = {
-        {
-          name = "codelldb Launch",
-          type = "codelldb",
-          request = "launch",
-          cwd = "${workspaceFolder}",
-          program = get_program,
-          args = get_args,
-          stopOnEntry = true,
-          console = "integratedTerminal",
-        },
-      }
+local function get_args()
+  local _args
+  vim.ui.input({
+    prompt = "Args: ",
+    default = vim.fn.getreg("+"),
+    complete = "file",
+  }, function(res)
+    _args = res
+  end)
+  return require("dap.utils").splitstr(_args)
+end
 
-      dap.configurations.c = dap.configurations.cpp
-      dap.configurations.rust = dap.configurations.cpp
-    end,
-    dependencies = {
-      {
-        "theHamsta/nvim-dap-virtual-text",
-        opts = {},
-        dependencies = { "nvim-treesitter/nvim-treesitter" },
-      },
-      "williamboman/mason.nvim",
-      {
-        "jay-babu/mason-nvim-dap.nvim",
-        opts = {
-          automatic_installation = false,
-          handlers = {},
-          ensure_installed = {},
-        },
-      },
-    },
+dap.configurations.cpp = {
+  {
+    name = "codelldb Launch",
+    type = "codelldb",
+    request = "launch",
+    cwd = "${workspaceFolder}",
+    program = get_program,
+    args = get_args,
+    stopOnEntry = true,
+    console = "integratedTerminal",
   },
 }
+
+dap.configurations.c = dap.configurations.cpp
+dap.configurations.rust = dap.configurations.cpp
+
+require("nvim-dap-virtual-text").setup({})
+require("mason-nvim-dap").setup({
+  automatic_installation = false,
+  handlers = {},
+  ensure_installed = {},
+})