feat(ui): use floating window for CursorSpinner

- Refactor CursorSpinner to render its spinner animation using a minimal-style floating window at the cursor position instead of an extmark-based virtual text overlay.

Author: sudo-tee

lua/opencode/quick_chat/spinner.lua

@@ -1,6 +1,11 @@
 local config = require('opencode.config')
 local Timer = require('opencode.ui.timer')
 
+---@class Timer
+---@field start function
+---@field stop function
+---@field is_running function
+
 ---@class CursorSpinner
 ---@field buf integer
 ---@field row integer
@@ -11,6 +16,8 @@ local Timer = require('opencode.ui.timer')
 ---@field timer Timer|nil
 ---@field active boolean
 ---@field frames string[]
+---@field float_win integer|nil
+---@field float_buf integer|nil
 local CursorSpinner = {}
 CursorSpinner.__index = CursorSpinner
 
@@ -24,27 +31,54 @@ function CursorSpinner.new(buf, row, col)
   self.current_frame = 1
   self.timer = nil
   self.active = true
+  self.float_win = nil
+  self.float_buf = nil
 
-  self.frames = config.values.ui.loading_animation and config.values.ui.loading_animation.frames
+  self.frames = config.ui.loading_animation and config.ui.loading_animation.frames
     or { '⠋', '⠙', '⠹', '⠸', '⠼', '⠴', '⠦', '⠧', '⠇', '⠏' }
 
+  self:create_float()
   self:render()
   self:start_timer()
   return self
 end
 
-function CursorSpinner:render()
+function CursorSpinner:create_float()
   if not self.active or not vim.api.nvim_buf_is_valid(self.buf) then
     return
   end
 
-  local frame = ' ' .. self.frames[self.current_frame]
-  self.extmark_id = vim.api.nvim_buf_set_extmark(self.buf, self.ns_id, self.row, self.col, {
-    id = self.extmark_id,
-    virt_text = { { frame .. ' ', 'Comment' } },
-    virt_text_pos = 'overlay',
-    right_gravity = false,
-  })
+  self.float_buf = vim.api.nvim_create_buf(false, true)
+
+  local win_config = self:get_float_config()
+
+  self.float_win = vim.api.nvim_open_win(self.float_buf, false, win_config)
+
+  vim.api.nvim_set_option_value('winhl', 'Normal:Comment', { win = self.float_win })
+  vim.api.nvim_set_option_value('wrap', false, { win = self.float_win })
+end
+
+function CursorSpinner:get_float_config()
+  return {
+    relative = 'cursor',
+    width = 3,
+    height = 1,
+    row = 0,
+    col = 2, -- 2 columns to the right of cursor
+    style = 'minimal',
+    border = 'rounded',
+    focusable = false,
+    zindex = 1000,
+  }
+end
+
+function CursorSpinner:render()
+  if not self.active or not self.float_buf or not vim.api.nvim_buf_is_valid(self.float_buf) then
+    return
+  end
+
+  local frame = ' ' .. self.frames[self.current_frame] .. ' '
+  vim.api.nvim_buf_set_lines(self.float_buf, 0, -1, false, { frame })
 end
 
 function CursorSpinner:next_frame()
@@ -53,7 +87,7 @@ end
 
 function CursorSpinner:start_timer()
   self.timer = Timer.new({
-    interval = 100, -- 10 FPS like the main loading animation
+    interval = 100, -- 10 FPS
     on_tick = function()
       if not self.active then
         return false
@@ -79,6 +113,14 @@ function CursorSpinner:stop()
     self.timer = nil
   end
 
+  if self.float_win and vim.api.nvim_win_is_valid(self.float_win) then
+    pcall(vim.api.nvim_win_close, self.float_win, true)
+  end
+
+  if self.float_buf and vim.api.nvim_buf_is_valid(self.float_buf) then
+    pcall(vim.api.nvim_buf_delete, self.float_buf, { force = true })
+  end
+
   if self.extmark_id and vim.api.nvim_buf_is_valid(self.buf) then
     pcall(vim.api.nvim_buf_del_extmark, self.buf, self.ns_id, self.extmark_id)
   end