feat(picker): Add a snacks picker with jj status command

lua/jj/picker/snacks.lua

@@ -0,0 +1,40 @@
+local utils = require("jj.utils")
+
+--- @class jj.picker.snacks
+local M = {}
+
+--- Displays the status files in a snacks picker
+---@param opts  jj.picker.config
+---@param files jj.picker.file[]
+function M.status(opts, files)
+	if not opts.snacks then
+		return utils.notify("Snacks picker is `disabled`", vim.log.levels.INFO)
+	end
+
+	local snacks = require("snacks")
+
+	local snacks_opts
+	-- If its true we default to an empty table
+	if opts.snacks == true then
+		snacks_opts = {}
+	else
+		--- Otherwise we get the table from the config
+		---@type table
+		snacks_opts = opts.snacks
+	end
+
+	local merged_opts = vim.tbl_deep_extend("force", snacks_opts, {
+		source = "jj",
+		items = files,
+		title = "JJ Status",
+		preview = function(ctx)
+			if ctx.item.file then
+				snacks.picker.preview.cmd(ctx.item.diff_cmd, ctx, {})
+			end
+		end,
+	})
+
+	snacks.picker.pick(merged_opts)
+end
+
+return M