fix: open no approval window for a site-connection prompt already answered (closes #287)

When a site-connection prompt was decided before the toolbar popup raised
for it had loaded, that popup was torn down, chrome.action.openPopup()
rejected, and the background opened its fallback window for the answered
approval and only then removed it. In the Chrome end-to-end suite the next
test could take that window for its own prompt and lose it under its wait.
openApprovalWindow() now returns before creating a window when the approval
is no longer pending.

The blocklist test clicked its self-closing Reject with a plain click; it
now clicks it as the other site Reject does, with the click witnessed.
README.md and the e2e workflow comment no longer name this issue as what
keeps e2e-chrome from being a required check.

Model: opus-5-5

.gitea/workflows/e2e.yml

@@ -22,11 +22,10 @@ on: [push]
 # These jobs REPORT, they do not gate. Whether a check blocks a merge is
 # Gitea branch protection, which this repo does not configure, so a failure
 # here is a red mark a reviewer has to account for rather than a hard
-# block. Making e2e-chrome a required check is blocked on the measured
-# flake in the dApp signing wait -- two of six runs of unmutated code on a
-# loaded machine -- tracked as
-# https://git.eeqj.de/sneak/AutistMask/issues/287. A gate that fails at
-# random teaches people to merge past red.
+# block. Making e2e-chrome a required check is blocked while reports of the
+# Chrome suite failing under load are still open; the "In CI" section of
+# README.md names them. A gate that fails at random teaches people to merge
+# past red.
 #
 # Nothing here may pass vacuously. There is no continue-on-error and no
 # `|| true`. Both scripts exit non-zero when docker is missing, when the