fix(actions): persist per-buffer render config across re-renders

[NeOzay]

Hi,
When a custom config is passed to actions.render(), store it as a buffer variable so that subsequent automatic re-renders (triggered by autocmds like ModeChanged, CursorMoved) reuse it instead of falling back to the global config.

[Copilot]

Pull request overview

This PR updates actions.render() so that when a custom render config is provided, it is remembered per-buffer and reused on subsequent automatic re-renders (e.g., from autocmds), instead of falling back to the global config.

Changes:

• Persist _config passed to actions.render() into a per-buffer variable.
• When _config is omitted on later calls, retrieve the stored per-buffer config and apply it via spec.tmp_setup().

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[OXY2DEV]

@NeOzay what's the use case for this?

Also, why buffer local variable? Shouldn't it be window local(some of the rendering logic is affected by window options) variable?

[NeOzay]

@OXY2DEV
Hi, I'm using the Snacks notifier and Markview with a different configuration than the global one to render the notification.
But when I focus on the notification, Markview re-renders it with the global configuration.

I'm doing it with this code, maybe I'm doing it wrong.

require("markview.actions").render(self.buf, nil, {                      
	markdown = {                                                           
		list_items = { indent_size = 1, shift_width = 1 },                   
		code_blocks = {                                                      
			label_direction = "right",
			style = "simple",                                                  
		},                                                                   
	},                                                                     
})

[NeOzay]

Also, my PR is more of a draft, I'm sure it's possible to implement this more cleanly.

[OXY2DEV]

@NeOzay isn't the notification buffer a nofile buffer, so it shouldn't be rendered by default.

Also, if for whatever reason you have ignore_buftypes = {}, you can still use preview.condition to stop markview from rendering in buffers you don't want it to render in.

[NeOzay]

I'm already using ignore_buftypes = {}.

To make it work, I'm using vim.treesitter.language.register("markdown", ft) to force the notifier to use the parser.

My problem is how I can specify a local configuration for a window.