feat: agent-02-kiosk Phase 1 - NFC UID migration + session service

- Migration 0025: kiosk_nfc_uid column on users table with partial unique index per company
- User model: kiosk_nfc_uid field after personnel_number
- New service: kiosk_session_service.py (Redis-based 15min sessions)
- New core module: app/core/redis.py (sync Redis client with ping-test)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/DEVLOG.md

@@ -487,3 +487,54 @@ Keine Commits in dieser Session.
 - frontend/src/pages/KioskDevicesPage.tsx | 412 +++++++++++++++++--------
 
 ---
+## 2026-05-24 12:22 – 12:24 (2m)
+**Beschreibung:** Claude Code Session
+**Projekt:** timemaster
+
+### Commits
+- 35fcea9 feat(kiosk): Stufe 3 – ServiceWorker, WebCrypto Setup-Flow, Kiosk-UI, 15 Security-Tests
+
+### Geänderte Dateien
+- DEVLOG.md                             |  20 ++
+- backend/tests/test_kiosk_security.py  | 387 ++++++++++++++++++++++++++++++++++
+- frontend/DEVLOG.md                    |  20 ++
+- frontend/public/kiosk-sw.js           | 187 ++++++++++++++++
+- frontend/src/App.tsx                  |   4 +
+- frontend/src/pages/KioskSetupPage.tsx | 307 +++++++++++++++++++++++++++
+- frontend/src/pages/KioskStampPage.tsx | 348 ++++++++++++++++++++++++++++++
+
+---
+## 2026-05-24 12:26 – 12:28 (1m)
+**Beschreibung:** Claude Code Session
+**Projekt:** frontend
+
+### Commits
+Keine Commits in dieser Session.
+
+### Geänderte Dateien
+- DEVLOG.md                             |  20 ++
+- backend/tests/test_kiosk_security.py  | 387 ++++++++++++++++++++++++++++++++++
+- frontend/DEVLOG.md                    |  20 ++
+- frontend/public/kiosk-sw.js           | 187 ++++++++++++++++
+- frontend/src/App.tsx                  |   4 +
+- frontend/src/pages/KioskSetupPage.tsx | 307 +++++++++++++++++++++++++++
+- frontend/src/pages/KioskStampPage.tsx | 348 ++++++++++++++++++++++++++++++
+
+---
+## 2026-05-24 12:31 – 12:31 (0m)
+**Beschreibung:** Claude Code Session
+**Projekt:** frontend
+
+### Commits
+Keine Commits in dieser Session.
+
+### Geänderte Dateien
+- DEVLOG.md                             |  20 ++
+- backend/tests/test_kiosk_security.py  | 387 ++++++++++++++++++++++++++++++++++
+- frontend/DEVLOG.md                    |  20 ++
+- frontend/public/kiosk-sw.js           | 187 ++++++++++++++++
+- frontend/src/App.tsx                  |   4 +
+- frontend/src/pages/KioskSetupPage.tsx | 307 +++++++++++++++++++++++++++
+- frontend/src/pages/KioskStampPage.tsx | 348 ++++++++++++++++++++++++++++++
+
+---