feat(plugins): add git-ai-commit, diffview, and reorganize keymaps

- Add AI-powered commit message generation with git-ai-commit plugin.
- Add diffview for side-by-side git diffs.
- Reorganize telescope keymaps (<leader><leader> for live_grep, <leader>/ for find_files).
- Update lazy.nvim imports to include plugins.extras.
- Add mago.nvim for PHP support.
- Update AI plugin with model configuration.

lua/plugins/extras/lazygit.lua

@@ -14,7 +14,6 @@ return {
   },
   dependencies = { 'nvim-lua/plenary.nvim' },
   keys = {
-    { '<leader>lg', '<cmd>LazyGit<cr>', desc = 'LazyGit' },
-    -- <C-g> is also mapped in config/keymaps.lua
+    { '<C-g>', '<cmd>LazyGit<cr>', desc = 'LazyGit' },
   },
 }