zotLook 1.3.4

Internal hardening. Nothing changes for a reader; this is the release the
plugin's own checks now stand behind.

The modules are closed. Each of the plugin's four modules is sealed or
frozen, and three fields that used to appear on first use are declared. That
is what lets the type checker — which now runs in npm test — see a misspelt
method name anywhere in the plugin, the mistake it could not see before.

A preference call loses two arguments it had carried since the XPCOM
days, ignored since Zotero 7. Comments that described two functions as
returning the opposite of what they return are corrected.

Requires Zotero 10 — the version zotLook is developed and tested against.
macOS 12+, or Linux with GNOME Sushi, or Windows with QuickLook running.