v0.165.0: Indítópult megosztása — guest launcher via capability URL (+ optional password, QR)

Mint a 160-bit capability URL (/s/<token>) serving a standalone read-only guest
launcher: same tiles, opens apps in new tabs, no account, no admin session.
Information only, zero control — every privilege stays behind each app's own auth.

- /s/ pre-auth pass-through (after the claim gate) + session-CSRF exemption; guest
  password POST carries its own pre-auth HMAC CSRF.
- Constant-time token match; empty stored token = disabled = byte-identical mux 404.
- Optional per-share password: separate bcrypt hash + own attempt map; signed cookie
  = HMAC(token|passwordHash) keyed with web.session_secret, so rotate/change invalidates.
- Guest labels ride the v0.164.0 ruling; never expose internal state vocabulary.
- Token redacted in logs (/s/<redacted>); never in CHANGELOG/REPORT/CONTEXT.
- Admin modal: copy-link, QR (go-qrcode), set/clear password, rotate, disable.
- Tests: Groups A-G (14) + 3 red-proofs verified red.

controller/go.mod

@@ -5,6 +5,7 @@ go 1.24.0
 require (
 	github.com/emersion/go-sasl v0.0.0-20241020182733-b788ff22d5a6
 	github.com/emersion/go-smtp v0.24.0
+	github.com/skip2/go-qrcode v0.0.0-20200617195104-da1b6568686e
 	golang.org/x/crypto v0.31.0
 	gopkg.in/yaml.v3 v3.0.1
 	modernc.org/sqlite v1.45.0