feat: agent-11 PR3 – Scheduler + Erinnerungs-Mails + Notification-Prefs

Geplante Erinnerungen (Feature-Parität mit Urlaubsverwaltung):

- APScheduler (AsyncIOScheduler) in der FastAPI-Lifespan; tägliche Jobs ab
  settings.reminder_hour. Redis-Tageslock gegen Doppelversand bei mehreren
  Prozessen; jeder Job mit eigener Session + RLS-Bypass.
- Drei Jobs (auch einzeln aufrufbar): offene Anträge an Genehmiger,
  Resturlaub-Verfall-Vorwarnung an Mitarbeiter, fehlende AU an HR.
- Pro-User notification_prefs (JSONB, opt-out); GET/PATCH /users/me/notification-prefs
  + ProfilePage-UI; Vertreter-Mail respektiert die Prefs.
- Manueller Trigger POST /companies/me/run-reminders (Admin) – gleiche Logik,
  firmen-scoped (testbar ohne Warten).
- Bugfix: GET-/PATCH-Urlaubskonto (update_balance) nutzte nicht existente
  Felder (base_days/carried_over_days/ip_address) → korrigiert auf
  entitled_days/carried_over/ip + company_id; available_days ergänzt.

Migration 0037 (users.notification_prefs). 188/188 Tests grün. Deployed 137 + 164.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/app/services/scheduler_service.py

@@ -0,0 +1,215 @@
+"""Geplante Erinnerungs-Jobs (agent-11 PR3).
+
+AsyncIOScheduler läuft im FastAPI-Event-Loop. Jeder Job öffnet eine eigene
+DB-Session mit RLS-Bypass (interner Job ohne Tenant-Kontext) und holt vor dem
+Versand einen Redis-Tageslock, damit bei mehreren Prozessen nicht doppelt
+gemailt wird. Die run_*-Funktionen sind ohne Scheduler aufrufbar (Tests +
+manueller Trigger über die API) und können auf eine Firma eingegrenzt werden.
+"""
+from __future__ import annotations
+
+import logging
+from datetime import date
+
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.config import settings
+from app.core.notifications import pref_enabled
+from app.models.absence import Absence, AbsenceStatus
+from app.models.absence_type import AbsenceCategory, AbsenceType
+from app.models.company import Company
+from app.models.user import User, UserRole
+from app.models.vacation_balance import VacationBalance
+from app.services.absence_service import absence_service
+from app.services.email_service import email_service
+
+log = logging.getLogger(__name__)
+
+_APPROVER_ROLES = (UserRole.MANAGER, UserRole.HR, UserRole.COMPANY_ADMIN)
+_HR_ROLES = (UserRole.HR, UserRole.COMPANY_ADMIN)
+
+_scheduler = None
+
+
+def _fmt(d: date) -> str:
+    return d.strftime("%d.%m.%Y")
+
+
+async def _active_companies(db: AsyncSession, company_id) -> list[Company]:
+    q = select(Company).where(Company.is_active.is_(True))
+    if company_id:
+        q = q.where(Company.id == company_id)
+    return list((await db.scalars(q)).all())
+
+
+async def _recipients(db: AsyncSession, company_id, roles) -> list[User]:
+    return list((await db.scalars(
+        select(User).where(
+            User.company_id == company_id,
+            User.is_active.is_(True),
+            User.role.in_(roles),
+        )
+    )).all())
+
+
+# ── Job-Logik ────────────────────────────────────────────────────────────────
+
+async def run_pending_approvals(db: AsyncSession, company_id=None) -> int:
+    """Zusammenfassung offener Anträge an alle Genehmiger je Firma. Liefert # Mails."""
+    sent = 0
+    for company in await _active_companies(db, company_id):
+        rows = (await db.execute(
+            select(Absence, User, AbsenceType)
+            .join(User, Absence.user_id == User.id)
+            .join(AbsenceType, Absence.type_id == AbsenceType.id)
+            .where(User.company_id == company.id, Absence.status == AbsenceStatus.PENDING)
+            .order_by(Absence.start_date)
+        )).all()
+        if not rows:
+            continue
+        items = [{
+            "user_name": u.full_name, "type_name": t.name,
+            "start": _fmt(a.start_date), "end": _fmt(a.end_date),
+            "working_days": float(a.working_days),
+        } for a, u, t in rows]
+
+        for approver in await _recipients(db, company.id, _APPROVER_ROLES):
+            if not approver.email or not pref_enabled(approver, "pending_approvals"):
+                continue
+            await email_service.send_pending_approvals_digest(approver, items, db)
+            sent += 1
+    return sent
+
+
+async def run_carryover_expiry(db: AsyncSession, company_id=None) -> int:
+    """Erinnert Mitarbeiter an bald verfallenden Resturlaub (Vorlauf konfigurierbar)."""
+    today = date.today()
+    year = today.year
+    sent = 0
+    for company in await _active_companies(db, company_id):
+        expires_at, expired = absence_service._carryover_expired(company, year)
+        if expires_at is None or expired:
+            continue
+        if (expires_at - today).days > settings.carryover_reminder_days:
+            continue
+        balances = (await db.execute(
+            select(VacationBalance, User)
+            .join(User, VacationBalance.user_id == User.id)
+            .where(
+                User.company_id == company.id, User.is_active.is_(True),
+                VacationBalance.year == year, VacationBalance.carried_over > 0,
+            )
+        )).all()
+        for bal, user in balances:
+            expiring = max(0, bal.carried_over - bal.used_days)  # Übertrag zuerst verbraucht
+            if expiring <= 0 or not user.email or not pref_enabled(user, "carryover_expiry"):
+                continue
+            await email_service.send_carryover_expiry_reminder(user, expiring, expires_at, db)
+            sent += 1
+    return sent
+
+
+async def run_certificate_overdue(db: AsyncSession, company_id=None) -> int:
+    """Meldet HR fehlende AU-Bescheinigungen (knüpft an agent-05)."""
+    today = date.today()
+    sent = 0
+    for company in await _active_companies(db, company_id):
+        rows = (await db.execute(
+            select(Absence, User)
+            .join(User, Absence.user_id == User.id)
+            .join(AbsenceType, Absence.type_id == AbsenceType.id)
+            .where(
+                User.company_id == company.id,
+                AbsenceType.category == AbsenceCategory.SICK,
+                Absence.certificate_required_by.isnot(None),
+                Absence.certificate_required_by < today,
+                Absence.certificate_received_at.is_(None),
+                Absence.status == AbsenceStatus.APPROVED,
+            )
+            .order_by(Absence.start_date)
+        )).all()
+        if not rows:
+            continue
+        items = [{
+            "user_name": u.full_name, "start": _fmt(a.start_date),
+            "due": _fmt(a.certificate_required_by),
+        } for a, u in rows]
+
+        for hr in await _recipients(db, company.id, _HR_ROLES):
+            if not hr.email or not pref_enabled(hr, "certificate_overdue"):
+                continue
+            await email_service.send_certificate_overdue_digest(hr, items, db)
+            sent += 1
+    return sent
+
+
+async def run_all_reminders(db: AsyncSession, company_id=None) -> dict:
+    return {
+        "pending_approvals": await run_pending_approvals(db, company_id),
+        "carryover_expiry": await run_carryover_expiry(db, company_id),
+        "certificate_overdue": await run_certificate_overdue(db, company_id),
+    }
+
+
+# ── Scheduler-Verdrahtung ────────────────────────────────────────────────────
+
+def _acquire_daily_lock(name: str) -> bool:
+    """True, wenn dieser Prozess den heutigen Job ausführen darf (Redis SET NX).
+    Ohne Redis: immer True (Single-Prozess-Annahme)."""
+    from app.core.redis import get_redis_client
+    redis = get_redis_client()
+    if redis is None:
+        return True
+    key = f"reminder_lock:{name}:{date.today().isoformat()}"
+    try:
+        return bool(redis.set(key, "1", nx=True, ex=23 * 3600))
+    except Exception as exc:
+        log.warning("Reminder-Lock fehlgeschlagen (%s) – führe trotzdem aus: %s", name, exc)
+        return True
+
+
+async def _run_job(name: str, fn) -> None:
+    if not _acquire_daily_lock(name):
+        log.info("Reminder-Job %s bereits von anderem Prozess übernommen.", name)
+        return
+    from sqlalchemy import text
+    from app.core.database import AsyncSessionLocal
+    try:
+        async with AsyncSessionLocal() as db:
+            await db.execute(text("SET LOCAL app.bypass_rls = 'on'"))
+            count = await fn(db)
+            await db.commit()
+        log.info("Reminder-Job %s: %s Mail(s) versendet.", name, count)
+    except Exception as exc:
+        log.exception("Reminder-Job %s fehlgeschlagen: %s", name, exc)
+
+
+def start() -> None:
+    global _scheduler
+    if _scheduler is not None:
+        return
+    try:
+        from apscheduler.schedulers.asyncio import AsyncIOScheduler
+        from apscheduler.triggers.cron import CronTrigger
+    except Exception as exc:
+        log.warning("APScheduler nicht verfügbar – Erinnerungen deaktiviert: %s", exc)
+        return
+
+    _scheduler = AsyncIOScheduler()
+    hour = settings.reminder_hour
+    _scheduler.add_job(_run_job, CronTrigger(hour=hour, minute=0),
+                       args=["pending_approvals", run_pending_approvals], id="pending_approvals")
+    _scheduler.add_job(_run_job, CronTrigger(hour=hour, minute=10),
+                       args=["carryover_expiry", run_carryover_expiry], id="carryover_expiry")
+    _scheduler.add_job(_run_job, CronTrigger(hour=hour, minute=20),
+                       args=["certificate_overdue", run_certificate_overdue], id="certificate_overdue")
+    _scheduler.start()
+    log.info("Reminder-Scheduler gestartet (täglich ab %02d:00 Uhr).", hour)
+
+
+def shutdown() -> None:
+    global _scheduler
+    if _scheduler is not None:
+        _scheduler.shutdown(wait=False)
+        _scheduler = None