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/web/auth/links.go

@@ -168,7 +168,8 @@ func (m *Module) HandleReset(w http.ResponseWriter, r *http.Request) {
 }
 
 // sendReset mails the account named username a reset link if its address is
-// confirmed, at most three an hour.
+// confirmed: not within resetSpacing of the last, five a day (then one
+// notice) and five an hour.
 func (m *Module) sendReset(username string) {
 	if username == "" || m.mailer == nil || m.cfg.Hostname == "" {
 		return