fix(nvim): disable noice cmdline/messages to stop popup flickering

noice's cmdline floating window was causing visible flicker when typing
:wq and other commands. Disable noice cmdline+messages entirely and
restore cmdheight=1 so native cmdline handles input stably.
noice still handles LSP and notifications via snacks.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

nvim/lua/config/options.lua

@@ -11,7 +11,7 @@ opt.cursorline = true           -- 高亮当前行
 opt.signcolumn = "yes"          -- 始终显示标记列（避免每次出现符号时布局跳动）
 opt.showmode = false            -- 不显示模式，由状态栏插件替代
 opt.laststatus = 3              -- 全局状态栏
-opt.cmdheight = 0               -- 命令行高度（noice.nvim 接管，设为 0 消除闪烁）
+opt.cmdheight = 1               -- 命令行高度
 opt.scrolloff = 10              -- 光标上下保留的行数
 opt.sidescrolloff = 10          -- 光标左右保留的列数
 opt.wrap = false                -- 不自动换行