v3.32.4: rebuild the link on card insertion (the first attempt)

v3.32.2 fixed the endless re-arm, but on Windows the first attempt
still failed on the old link (seen in the confirmation log: the
"self._con.connect()" traceback) and only the retry recovered - a failed
init, a 2-4 s delay and a traceback in the log.

The monitor's insert path now marks the transport stale under
_CARD_LOCK, so the first equip attempt rebuilds the PC/SC link.  It also
covers a link created at a cardless startup (never connected).  The
rebuild still happens in the equip worker, never in the pyscard monitor
thread, and _ensure_transport releases the old link first.

Docs: the READMEs' troubleshooting bullet.
Tests: an insertion marks the transport for the rebuild.
1014 Python + 953 frontend green; simple-v462.

frontend/sw.js

@@ -1,4 +1,4 @@
-const CACHE = 'simple-v460';
+const CACHE = 'simple-v462';
 const URLS = [
   'index.html',
   'help.html',