Add per-user TOTP 2FA, client-level user assignment, self-service portal

- TOTP (RFC 6238, stdlib-only) enrollment in profile, login step-up,
  admin emergency reset.
- Admins can grant a user visibility into individual clients
  (User.ClientIDs) in addition to whole-server access (User.ServerIDs).
- New "My Access" page: non-admin users see only their assigned clients
  (view/QR/download only, no management), reachable from the main nav.
- GetUser/GetUsers now redact TOTPSecret before returning JSON.

No Go toolchain was available while writing this - not yet build-verified.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PvrfUytqd74H6WcQkRzFM4

DEVLOG.md

@@ -2439,3 +2439,83 @@ Keine Commits in dieser Session.
 - opnsense/parse.go | 78 +++++++++++++++++++++++++++++++++++++++++++++---------------------------------
 
 ---
+## 2026-07-25 00:18 – 00:19 (0m)
+**Beschreibung:** Claude Code Session
+**Projekt:** wireguard-ui-multi
+
+### Commits
+- c29edfd Add wg-quick/systemctl service control and bulk-delete list views
+
+### Geänderte Dateien
+- DEVLOG.md                     | 237 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+- handler/routes.go             |  84 +++++++++++++++++++++++++++++++++++++++++++++++
+- main.go                       |   4 +++
+- templates/server_clients.html | 174 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
+- templates/servers.html        | 274 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+- wireguard/service.go          |  88 +++++++++++++++++++++++++++++++++++++++++++++++++
+
+---
+## 2026-07-25 00:21 – 00:21 (0m)
+**Beschreibung:** Claude Code Session
+**Projekt:** wireguard-ui-multi
+
+### Commits
+Keine Commits in dieser Session.
+
+### Geänderte Dateien
+- DEVLOG.md                     | 237 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+- handler/routes.go             |  84 +++++++++++++++++++++++++++++++++++++++++++++++
+- main.go                       |   4 +++
+- templates/server_clients.html | 174 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
+- templates/servers.html        | 274 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+- wireguard/service.go          |  88 +++++++++++++++++++++++++++++++++++++++++++++++++
+
+---
+## 2026-07-25 00:28 – 00:33 (5m)
+**Beschreibung:** Claude Code Session
+**Projekt:** wireguard-ui-multi
+
+### Commits
+Keine Commits in dieser Session.
+
+### Geänderte Dateien
+- DEVLOG.md                     | 237 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+- handler/routes.go             |  84 +++++++++++++++++++++++++++++++++++++++++++++++
+- main.go                       |   4 +++
+- templates/server_clients.html | 174 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
+- templates/servers.html        | 274 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+- wireguard/service.go          |  88 +++++++++++++++++++++++++++++++++++++++++++++++++
+
+---
+## 2026-07-25 00:34 – 00:34 (0m)
+**Beschreibung:** Claude Code Session
+**Projekt:** wireguard-ui-multi
+
+### Commits
+Keine Commits in dieser Session.
+
+### Geänderte Dateien
+- DEVLOG.md                     | 237 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+- handler/routes.go             |  84 +++++++++++++++++++++++++++++++++++++++++++++++
+- main.go                       |   4 +++
+- templates/server_clients.html | 174 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
+- templates/servers.html        | 274 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+- wireguard/service.go          |  88 +++++++++++++++++++++++++++++++++++++++++++++++++
+
+---
+## 2026-07-25 00:35 – 00:35 (0m)
+**Beschreibung:** Claude Code Session
+**Projekt:** wireguard-ui-multi
+
+### Commits
+Keine Commits in dieser Session.
+
+### Geänderte Dateien
+- DEVLOG.md                     | 237 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+- handler/routes.go             |  84 +++++++++++++++++++++++++++++++++++++++++++++++
+- main.go                       |   4 +++
+- templates/server_clients.html | 174 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
+- templates/servers.html        | 274 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+- wireguard/service.go          |  88 +++++++++++++++++++++++++++++++++++++++++++++++++
+
+---