style(gh): cleanup

lua/snacks/picker/source/gh.lua

@@ -141,12 +141,16 @@ function M.diff(opts, ctx)
   if opts.repo then
     vim.list_extend(args, { "--repo", opts.repo })
   end
-  opts.previewers.diff.style = "fancy"
+
+  opts.previewers.diff.style = "fancy" -- only fancy style support inline review comments
+
   local Render = require("snacks.gh.render")
   local Diff = require("snacks.picker.source.diff")
   ---@async
   return function(cb)
     local item = Api.get({ type = "pr", repo = opts.repo, number = opts.pr })
+
+    -- fetch on the main thread since rendering uses non-fast APIs
     local annotations = ctx.async:schedule(function()
       return Render.annotations(item)
     end)
@@ -159,9 +163,7 @@ function M.diff(opts, ctx)
         annotations = annotations,
       }),
       ctx
-    )(function(it)
-      cb(it)
-    end)
+    )(cb)
   end
 end