Remove edge glow; prefill MCMS URL from env; drop self-signed-cert option

- Remove the animated neon edge-glow entirely (HTML element + CSS) — it
  couldn't be made to follow the border reliably on iOS Safari.
- Add PFW_MCMS_URL: the web server prefills the login "Host URL" field with
  it (injected as the input's value in the served index; still editable).
  Documented in env.example + web README.
- Remove the "Accept self-signed TLS certificate" option: the checkbox is
  gone and both backends now always use rejectUnauthorized:true — MCMS must
  present a valid certificate. Dropped the acceptSelfSigned plumbing from the
  renderer and both login handlers.

Docs: CLAUDE.md (drop edge-glow section, update login note) + web README.

Verified: node --check; no stale refs (in-self-signed / acceptSelfSigned /
edge-glow / beamspin); served index carries value="…" only when
PFW_MCMS_URL is set, and no self-signed checkbox.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

web/deploy/pon-fleet-web.env.example

@@ -2,6 +2,10 @@
 # Copy to /etc/pon-fleet-web.env and edit. All values are optional; the
 # defaults shown are what the server uses if a line is omitted.
 
+# Prefill the login "Host URL" field so operators don't type it each time.
+# (Still editable in the form.) Use the MCMS PON Manager root URL.
+#PFW_MCMS_URL=https://mcms.example.net
+
 # Listen port.
 #PORT=8080