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/app/password.go

@@ -13,7 +13,8 @@ const passwordBytes = 24
 
 // generatePassword returns a strong, URL-safe random password for an
 // application's SASL account. The panel generates it, shows it once and never
-// stores the plaintext (security.md); sasldb2 keeps only the hashed form.
+// stores it in its own database; sasldb2 keeps it, in the clear, as Cyrus
+// does for PLAIN and LOGIN (security.md).
 //
 // base64url output keeps the password to a safe ASCII alphabet with no shell or
 // SMTP-special characters, so it survives being typed into client configuration