feat(run): stop the flutter process when exiting nvim

lua/flutter-tools.lua

@@ -130,6 +130,7 @@ local function setup_autocommands()
     pattern = { "*" },
     callback = function()
       dev_tools.stop()
+      if package.loaded["flutter-tools.commands"] then commands.on_exit() end
       if package.loaded["flutter-tools.widget_preview"] then widget_preview.on_exit() end
     end,
   })

lua/flutter-tools/commands.lua

@@ -28,6 +28,7 @@ local current_device = nil
 ---@field cleanup fun(funner: flutter.Runner)
 ---@field send fun(runner: flutter.Runner, cmd:string, quiet: boolean?, on_response: fun(response: any)|nil)
 ---@field attach fun(runner: flutter.Runner, paths:table, args:table, cwd:string, on_run_data:fun(is_err:boolean, data:string), on_run_exit:fun(data:string[], args: table, project_conf: flutter.ProjectConfig?,launch_config: dap.Configuration?))
+---@field stop? fun(runner: flutter.Runner)
 
 ---@type flutter.Runner?
 local runner = nil
@@ -65,6 +66,10 @@ function M.current_device() return current_device end
 
 function M.is_running() return runner ~= nil and runner:is_running() end
 
+function M.on_exit()
+  if runner and runner.stop then runner:stop() end
+end
+
 local function match_error_string(line)
   if not line then return false end
   -- match the error string if no devices are setup

lua/flutter-tools/runners/job_runner.lua

@@ -74,6 +74,14 @@ end
 
 function JobRunner:cleanup() run_job = nil end
 
+-- SIGTERM lets the flutter tool stop the app (or only detach, when attached)
+-- before exiting; closing stdin alone leaves it running.
+function JobRunner:stop()
+  if not run_job or not run_job.pid then return end
+  vim.uv.kill(run_job.pid, vim.uv.constants.SIGTERM)
+  vim.wait(3000, function() return run_job == nil or run_job.is_shutdown end)
+end
+
 function JobRunner:attach(paths, args, cwd, on_run_data, on_run_exit)
   local command = paths.flutter_bin
   local command_args = args