docs, comments: the drift the audit listed (audit 2026-10-17, stage 6)

The lines under "Doc and comment drift" that the findings' own commits
did not already fix:
- security.md: a newer confirmation link replaces the older, a reset link
  is not replaced; html/template renders every page (no themes); the
  container keeps eight capabilities, named, not "KILL".
- architecture.md: ImportKey writes over a name's key, as an import must;
  the error text reaches the browser on the Backup page's import refusal.
- guide: with Caddy the key is in Caddy's data, so a full backup refuses
  until certs/ holds a copy (or back up caddy-data).
- comments: sasldb2 holds application passwords in the clear (store,
  app/password.go); texthash folds ASCII (sender.go); the supervisor
  socket's group is supervisor (rpc.go); cert-reload's OpenSSL measurement
  was 3.0.x of bookworm; sendReset's limits (links.go).
Migration 0013's comment stays as shipped.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/supervisor/rpc.go

@@ -15,7 +15,7 @@ import (
 )
 
 // socketPath is supervisord's control socket: build/supervisord.conf,
-// [unix_http_server] file=, group selfpost, which the panel is in.
+// [unix_http_server] file=, group supervisor, whose one member is the panel.
 const socketPath = "/run/supervisor.sock"
 
 // runOnceFor bounds RunOnce: a reload that is still running after it is