feat(phase-9): email dispatcher — HTML templates, delivery log, test endpoint

Backend:
- app/models/email_log.py: EmailLog table (school_id, to, subject, type, status,
  error, sent_at) with EmailType + EmailStatus enums
- migrations/002_phase9_email_logs.py: Alembic migration for email_logs table
- app/templates/email/: 6 Jinja2 HTML templates — base layout, invoice,
  low_credit, license_expiry, overdue_warning, suspension
- app/services/email.py: enhanced send_email() — accepts template_name+context
  for HTML rendering, logs every attempt to email_logs, retries up to 3x on
  transient SMTP failure with exponential backoff
- app/routers/email.py: GET /api/email/logs (paginated, filterable by type/status/school),
  POST /api/email/test (send test email, super admin)
- tasks/billing.py: invoice + overdue warning + suspension emails now use HTML templates
- tasks/sms.py: low credit alert now uses HTML template
- tasks/license.py: expiry warning now uses HTML template
- app/main.py + migrations/env.py: wire in email_log model + email router

Frontend:
- EmailLogsPage.vue: table with to/subject/type badge/status badge/sent_at/error,
  type+status filters, pagination, Send Test Email modal
- router/index.ts: /email-logs route
- AppSidebar.vue: Email Logs nav item
- api.ts: getEmailLogs, sendTestEmail

backend/app/main.py

@@ -5,10 +5,10 @@ from fastapi.middleware.cors import CORSMiddleware
 
 from app.database import engine, Base
 # Import all models so Alembic/SQLAlchemy picks them up
-from app.models import user, school, license, sms, billing, ticket, audit, announcement  # noqa
+from app.models import user, school, license, sms, billing, ticket, audit, announcement, email_log  # noqa
 
 from app.routers import auth, schools, licenses, sms as sms_router, billing as billing_router
-from app.routers import tickets, users, dashboard, school_portal, announcements, sync
+from app.routers import tickets, users, dashboard, school_portal, announcements, sync, email as email_router
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):
@@ -44,6 +44,7 @@ app.include_router(dashboard.router)
 app.include_router(school_portal.router)
 app.include_router(announcements.router)
 app.include_router(sync.router)
+app.include_router(email_router.router)
 
 @app.get("/api/health")
 async def health():

backend/app/models/email_log.py

@@ -0,0 +1,42 @@
+"""Email delivery log model."""
+import uuid
+import enum
+from datetime import datetime, timezone
+from sqlalchemy import String, DateTime, Enum as SAEnum, ForeignKey, Text
+from sqlalchemy.orm import Mapped, mapped_column
+from app.database import Base
+
+
+class EmailStatus(str, enum.Enum):
+    sent = "sent"
+    failed = "failed"
+
+
+class EmailType(str, enum.Enum):
+    invoice = "invoice"
+    low_credit = "low_credit"
+    license_expiry = "license_expiry"
+    overdue_warning = "overdue_warning"
+    suspension = "suspension"
+    monthly_report = "monthly_report"
+    welcome = "welcome"
+    test = "test"
+    other = "other"
+
+
+class EmailLog(Base):
+    __tablename__ = "email_logs"
+
+    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
+    school_id: Mapped[str | None] = mapped_column(
+        String(36), ForeignKey("schools.id", ondelete="SET NULL"), nullable=True, index=True
+    )
+    to_email: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
+    subject: Mapped[str] = mapped_column(String(500), nullable=False)
+    email_type: Mapped[EmailType] = mapped_column(SAEnum(EmailType), default=EmailType.other, nullable=False, index=True)
+    status: Mapped[EmailStatus] = mapped_column(SAEnum(EmailStatus), nullable=False, index=True)
+    error_message: Mapped[str | None] = mapped_column(Text, nullable=True)
+    sent_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
+    )

backend/app/routers/email.py

@@ -0,0 +1,94 @@
+"""Email log viewer and test-email endpoint."""
+from typing import Optional
+from fastapi import APIRouter, Depends, Query
+from pydantic import BaseModel, EmailStr
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy import select, func, desc
+
+from app.auth.dependencies import require_super_admin
+from app.database import get_db
+from app.models.user import HubUser
+from app.models.email_log import EmailLog, EmailType, EmailStatus
+
+router = APIRouter(prefix="/api/email", tags=["email"])
+
+
+@router.get("/logs")
+async def list_email_logs(
+    email_type: Optional[EmailType] = Query(None),
+    status: Optional[EmailStatus] = Query(None),
+    school_id: Optional[str] = Query(None),
+    page: int = Query(1, ge=1),
+    per_page: int = Query(50, ge=1, le=200),
+    _admin: HubUser = Depends(require_super_admin),
+    db: AsyncSession = Depends(get_db),
+):
+    """Paginated email delivery history — super admin only."""
+    stmt = select(EmailLog).order_by(desc(EmailLog.created_at))
+
+    if email_type:
+        stmt = stmt.where(EmailLog.email_type == email_type)
+    if status:
+        stmt = stmt.where(EmailLog.status == status)
+    if school_id:
+        stmt = stmt.where(EmailLog.school_id == school_id)
+
+    total = (await db.execute(select(func.count()).select_from(stmt.subquery()))).scalar_one()
+    logs = (await db.execute(stmt.offset((page - 1) * per_page).limit(per_page))).scalars().all()
+
+    return {
+        "items": [
+            {
+                "id": log.id,
+                "school_id": log.school_id,
+                "to_email": log.to_email,
+                "subject": log.subject,
+                "email_type": log.email_type.value,
+                "status": log.status.value,
+                "error_message": log.error_message,
+                "sent_at": log.sent_at.isoformat() if log.sent_at else None,
+                "created_at": log.created_at.isoformat(),
+            }
+            for log in logs
+        ],
+        "total": total,
+        "page": page,
+        "per_page": per_page,
+    }
+
+
+class TestEmailBody(BaseModel):
+    to: EmailStr
+
+
+@router.post("/test")
+async def send_test_email(
+    body: TestEmailBody,
+    _admin: HubUser = Depends(require_super_admin),
+):
+    """Send a test email to verify SMTP configuration."""
+    from app.services.email import send_email
+
+    success = send_email(
+        to=body.to,
+        subject="TapTrack Hub — SMTP Test Email",
+        body=(
+            "This is a test email from TapTrack Hub.\n\n"
+            "If you received this, your SMTP configuration is working correctly.\n\n"
+            "TapTrack Hub Team"
+        ),
+        html=(
+            "<div style='font-family:sans-serif;max-width:480px;margin:32px auto;padding:24px;"
+            "background:#fff;border:1px solid #e2e8f0;border-radius:12px'>"
+            "<h2 style='color:#1e40af;margin:0 0 16px'>TapTrack Hub — SMTP Test</h2>"
+            "<p style='color:#334155'>This is a test email from <strong>TapTrack Hub</strong>.</p>"
+            "<p style='color:#334155'>If you received this, your SMTP configuration is working correctly.</p>"
+            "<p style='color:#94a3b8;font-size:12px;margin-top:24px'>TapTrack Hub Team</p>"
+            "</div>"
+        ),
+        email_type="test",
+    )
+
+    if success:
+        return {"message": f"Test email sent successfully to {body.to}"}
+    return {"message": "Failed to send test email — check SMTP configuration and server logs"}

backend/app/services/email.py

@@ -1,32 +1,154 @@
-"""Simple SMTP email service."""
+"""Email service — SMTP delivery with HTML templates and delivery logging."""
 import smtplib
 import logging
+import time
+import uuid
+from datetime import datetime, timezone
 from email.mime.text import MIMEText
 from email.mime.multipart import MIMEMultipart
+from pathlib import Path
+from typing import Optional
+
 from app.config import settings
 
 logger = logging.getLogger(__name__)
 
-def send_email(to: str, subject: str, body: str, html: str | None = None) -> bool:
-    """Send email via configured SMTP. Returns True on success."""
-    if not settings.SMTP_HOST:
-        logger.warning(f"SMTP not configured — would send to {to}: {subject}")
-        return False
+TEMPLATE_DIR = Path(__file__).parent.parent / "templates"
+
+
+def _render_template(template_name: str, context: dict) -> str:
+    """Render a Jinja2 HTML email template. Returns empty string on failure."""
     try:
-        msg = MIMEMultipart("alternative")
-        msg["Subject"] = subject
-        msg["From"] = settings.SMTP_FROM
-        msg["To"] = to
-        msg.attach(MIMEText(body, "plain"))
-        if html:
-            msg.attach(MIMEText(html, "html"))
-        with smtplib.SMTP(settings.SMTP_HOST, settings.SMTP_PORT) as smtp:
-            smtp.starttls()
-            if settings.SMTP_USER:
-                smtp.login(settings.SMTP_USER, settings.SMTP_PASSWORD)
-            smtp.sendmail(settings.SMTP_FROM, [to], msg.as_string())
-        logger.info(f"Email sent to {to}: {subject}")
-        return True
+        from jinja2 import Environment, FileSystemLoader
+        env = Environment(loader=FileSystemLoader(str(TEMPLATE_DIR)), autoescape=True)
+        tmpl = env.get_template(template_name)
+        return tmpl.render(**context)
     except Exception as e:
-        logger.error(f"Email failed to {to}: {e}")
+        logger.warning("Template render failed (%s): %s", template_name, e)
+        return ""
+
+
+def _log_email(
+    to: str,
+    subject: str,
+    email_type: str,
+    status: str,
+    school_id: Optional[str] = None,
+    error_message: Optional[str] = None,
+) -> None:
+    """Write an email delivery record to email_logs. Best-effort — never raises."""
+    try:
+        import os
+        from sqlalchemy import create_engine
+        from sqlalchemy.orm import sessionmaker
+        from app.models.email_log import EmailLog, EmailStatus, EmailType
+
+        db_url = os.getenv("DATABASE_URL", "postgresql://postgres:postgres@db:5432/taptrack_hub")
+        engine = create_engine(
+            db_url.replace("postgresql+asyncpg://", "postgresql://"),
+            pool_pre_ping=True,
+            pool_size=1,
+            max_overflow=0,
+        )
+        Session = sessionmaker(bind=engine)
+        db = Session()
+        try:
+            # Map type string to enum, default to 'other'
+            try:
+                etype = EmailType(email_type)
+            except ValueError:
+                etype = EmailType.other
+
+            log = EmailLog(
+                id=str(uuid.uuid4()),
+                school_id=school_id,
+                to_email=to,
+                subject=subject,
+                email_type=etype,
+                status=EmailStatus(status),
+                error_message=error_message,
+                sent_at=datetime.now(timezone.utc) if status == "sent" else None,
+                created_at=datetime.now(timezone.utc),
+            )
+            db.add(log)
+            db.commit()
+        finally:
+            db.close()
+            engine.dispose()
+    except Exception as e:
+        logger.debug("Email log write failed: %s", e)
+
+
+def send_email(
+    to: str,
+    subject: str,
+    body: str,
+    html: Optional[str] = None,
+    template_name: Optional[str] = None,
+    context: Optional[dict] = None,
+    email_type: str = "other",
+    school_id: Optional[str] = None,
+    max_retries: int = 3,
+) -> bool:
+    """
+    Send an email via configured SMTP.
+
+    Priority order for HTML content:
+      1. `html` parameter (raw HTML string)
+      2. `template_name` + `context` (rendered Jinja2 template)
+      3. `body` only (plain text)
+
+    Logs every attempt to email_logs table.
+    Retries up to `max_retries` times on transient SMTP failure.
+
+    Returns True on success.
+    """
+    if not settings.SMTP_HOST:
+        logger.warning("SMTP not configured — would send to %s: %s", to, subject)
+        _log_email(to, subject, email_type, "failed", school_id, "SMTP not configured")
         return False
+
+    # Resolve HTML content
+    html_content = html
+    if not html_content and template_name:
+        ctx = context or {}
+        ctx.setdefault("subject", subject)
+        ctx.setdefault("portal_url", settings.HUB_BASE_URL)
+        html_content = _render_template(template_name, ctx)
+
+    last_error: Optional[str] = None
+
+    for attempt in range(1, max_retries + 1):
+        try:
+            msg = MIMEMultipart("alternative")
+            msg["Subject"] = subject
+            msg["From"] = settings.SMTP_FROM
+            msg["To"] = to
+            msg.attach(MIMEText(body, "plain"))
+            if html_content:
+                msg.attach(MIMEText(html_content, "html"))
+
+            with smtplib.SMTP(settings.SMTP_HOST, settings.SMTP_PORT) as smtp:
+                smtp.ehlo()
+                smtp.starttls()
+                smtp.ehlo()
+                if settings.SMTP_USER:
+                    smtp.login(settings.SMTP_USER, settings.SMTP_PASSWORD)
+                smtp.sendmail(settings.SMTP_FROM, [to], msg.as_string())
+
+            logger.info("Email sent to %s: %s", to, subject)
+            _log_email(to, subject, email_type, "sent", school_id)
+            return True
+
+        except smtplib.SMTPException as e:
+            last_error = str(e)
+            logger.warning("SMTP attempt %d/%d failed for %s: %s", attempt, max_retries, to, e)
+            if attempt < max_retries:
+                time.sleep(2 ** attempt)  # exponential backoff: 2s, 4s
+        except Exception as e:
+            last_error = str(e)
+            logger.error("Email send failed for %s: %s", to, e)
+            break  # Non-SMTP errors don't retry
+
+    _log_email(to, subject, email_type, "failed", school_id, last_error)
+    return False

backend/app/tasks/billing.py

@@ -136,20 +136,29 @@ def send_invoice_email_task(invoice_id: str):
         if not school or not school.billing_email:
             return
 
-        body = (
+        plain = (
             f"Dear {school.contact_name or school.name},\n\n"
-            f"Please find your invoice {inv.invoice_number} for the period "
-            f"{inv.billing_period_start} to {inv.billing_period_end}.\n\n"
-            f"Amount Due: PHP {float(inv.total_amount):,.2f}\n"
-            f"Due Date: {inv.due_date or 'Upon receipt'}\n\n"
-            f"Please log in to your TapTrack Hub school portal to view and download your invoice:\n"
-            f"{_hub_url()}/portal/billing\n\n"
-            f"Thank you,\nTapTrack Hub Team"
+            f"Your invoice {inv.invoice_number} for PHP {float(inv.total_amount):,.2f} "
+            f"covering {inv.billing_period_start} to {inv.billing_period_end} is ready.\n"
+            f"Due: {inv.due_date or 'Upon receipt'}\n\n"
+            f"Log in: {_hub_url()}/portal/billing\n\nTapTrack Hub Team"
         )
         send_email(
             to=school.billing_email,
             subject=f"Invoice {inv.invoice_number} — TapTrack Hub",
-            body=body,
+            body=plain,
+            template_name="email/invoice.html",
+            context={
+                "contact_name": school.contact_name or school.name,
+                "school_name": school.name,
+                "invoice_number": inv.invoice_number,
+                "period_start": str(inv.billing_period_start),
+                "period_end": str(inv.billing_period_end),
+                "amount": f"{float(inv.total_amount):,.2f}",
+                "due_date": str(inv.due_date) if inv.due_date else "Upon receipt",
+            },
+            email_type="invoice",
+            school_id=school.id,
         )
         inv.email_sent_at = datetime.now(timezone.utc)
         if inv.status == InvoiceStatus.draft:
@@ -209,17 +218,30 @@ def check_overdue():
         for inv in warn_invoices:
             school = db.get(School, inv.school_id)
             if school and school.billing_email:
+                days_overdue = (today - inv.due_date).days
+                days_until_suspension = max(0, 30 - days_overdue)
                 send_email(
                     to=school.billing_email,
                     subject=f"[TapTrack Hub] Overdue Invoice — {inv.invoice_number}",
                     body=(
                         f"Dear {school.contact_name or school.name},\n\n"
-                        f"Your invoice {inv.invoice_number} for PHP {float(inv.total_amount):,.2f} "
-                        f"was due on {inv.due_date} and is now overdue.\n\n"
-                        f"Please settle this invoice immediately to avoid account suspension.\n\n"
-                        f"Log in to your portal: {_hub_url()}/portal/billing\n\n"
-                        f"TapTrack Hub Team"
+                        f"Invoice {inv.invoice_number} (PHP {float(inv.total_amount):,.2f}) "
+                        f"was due on {inv.due_date} and is now overdue.\n"
+                        f"Please settle immediately to avoid suspension.\n\n"
+                        f"Portal: {_hub_url()}/portal/billing\n\nTapTrack Hub Team"
                     ),
+                    template_name="email/overdue_warning.html",
+                    context={
+                        "contact_name": school.contact_name or school.name,
+                        "school_name": school.name,
+                        "invoice_number": inv.invoice_number,
+                        "amount": f"{float(inv.total_amount):,.2f}",
+                        "due_date": str(inv.due_date),
+                        "days_overdue": days_overdue,
+                        "days_until_suspension": days_until_suspension,
+                    },
+                    email_type="overdue_warning",
+                    school_id=school.id,
                 )
         logger.info("Sent %d overdue warning emails", len(warn_invoices))
 
@@ -249,14 +271,21 @@ def check_overdue():
                         to=school.billing_email,
                         subject=f"[TapTrack Hub] Account Suspended — Invoice {inv.invoice_number}",
                         body=(
-                            f"Dear {school.contact_name or school.name},\n\n"
-                            f"Your TapTrack account has been suspended due to unpaid invoice "
-                            f"{inv.invoice_number} (PHP {float(inv.total_amount):,.2f}), "
-                            f"which was due on {inv.due_date}.\n\n"
-                            f"SMS notifications and automated reports are now disabled.\n\n"
-                            f"To restore service, please contact support@taptrack.io immediately.\n\n"
-                            f"TapTrack Hub Team"
+                            f"Your TapTrack account for {school.name} has been suspended.\n"
+                            f"Invoice {inv.invoice_number} (PHP {float(inv.total_amount):,.2f}) "
+                            f"was due on {inv.due_date} and remains unpaid.\n\n"
+                            f"Contact support@taptrack.io to restore service."
                         ),
+                        template_name="email/suspension.html",
+                        context={
+                            "contact_name": school.contact_name or school.name,
+                            "school_name": school.name,
+                            "invoice_number": inv.invoice_number,
+                            "amount": f"{float(inv.total_amount):,.2f}",
+                            "due_date": str(inv.due_date),
+                        },
+                        email_type="suspension",
+                        school_id=school.id,
                     )
 
         db.commit()

backend/app/tasks/license.py

@@ -6,6 +6,7 @@ from app.worker import celery_app
 
 logger = logging.getLogger(__name__)
 
+
 @celery_app.task(name="license.check_expiry")
 def check_expiry():
     """Send expiry warning emails for licenses expiring in 30, 14, or 7 days."""
@@ -34,7 +35,20 @@ def check_expiry():
                     send_email(
                         to=school.billing_email,
                         subject=f"[TapTrack Hub] License expires in {days_ahead} days — {school.name}",
-                        body=f"Your TapTrack license for {school.name} expires on {lic.expires_at}. Please contact us to renew.",
+                        body=(
+                            f"Your TapTrack license for {school.name} expires on {lic.expires_at} "
+                            f"({days_ahead} days remaining). Please contact us to renew."
+                        ),
+                        template_name="email/license_expiry.html",
+                        context={
+                            "contact_name": school.contact_name or school.name,
+                            "school_name": school.name,
+                            "license_key": lic.key,
+                            "expires_at": str(lic.expires_at),
+                            "days_left": days_ahead,
+                        },
+                        email_type="license_expiry",
+                        school_id=school.id,
                     )
         db.commit()
     finally:

backend/app/tasks/sms.py

@@ -146,7 +146,20 @@ def send_low_credit_alert(school_id: str):
             send_email(
                 to=school.billing_email,
                 subject=f"[TapTrack Hub] Low SMS Credits — {school.name}",
-                body=f"Your SMS credit balance for {school.name} is low ({float(school.sms_credits):.0f} remaining). Please top up to continue sending SMS notifications.",
+                body=(
+                    f"Your SMS credit balance for {school.name} is low "
+                    f"({float(school.sms_credits):.0f} credits remaining). "
+                    f"Please top up to continue sending SMS notifications."
+                ),
+                template_name="email/low_credit.html",
+                context={
+                    "contact_name": school.contact_name or school.name,
+                    "school_name": school.name,
+                    "credits_remaining": int(float(school.sms_credits)),
+                    "threshold": school.sms_credit_low_threshold,
+                },
+                email_type="low_credit",
+                school_id=school.id,
             )
     finally:
         db.close()

backend/app/templates/email/base.html

@@ -0,0 +1,45 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="UTF-8">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+<title>{{ subject }}</title>
+<style>
+  body { margin: 0; padding: 0; background: #f1f5f9; font-family: "Helvetica Neue", Helvetica, Arial, sans-serif; }
+  .wrapper { max-width: 600px; margin: 32px auto; background: #ffffff; border-radius: 12px; overflow: hidden; box-shadow: 0 2px 12px rgba(0,0,0,0.08); }
+  .header { background: #1e40af; padding: 24px 32px; }
+  .header h1 { color: #ffffff; font-size: 18px; font-weight: 700; margin: 0; letter-spacing: -0.3px; }
+  .header p { color: #93c5fd; font-size: 12px; margin: 4px 0 0; }
+  .body { padding: 32px; color: #334155; font-size: 14px; line-height: 1.7; }
+  .body h2 { color: #0f172a; font-size: 18px; font-weight: 700; margin: 0 0 16px; }
+  .body p { margin: 0 0 14px; }
+  .body a { color: #2563eb; }
+  .info-box { background: #f8fafc; border: 1px solid #e2e8f0; border-radius: 8px; padding: 16px 20px; margin: 20px 0; }
+  .info-box .row { display: flex; justify-content: space-between; padding: 5px 0; border-bottom: 1px solid #f1f5f9; font-size: 13px; }
+  .info-box .row:last-child { border-bottom: none; }
+  .info-box .label { color: #64748b; }
+  .info-box .value { font-weight: 600; color: #0f172a; }
+  .btn { display: inline-block; background: #2563eb; color: #ffffff !important; text-decoration: none; padding: 10px 24px; border-radius: 8px; font-weight: 600; font-size: 13px; margin: 8px 0; }
+  .alert-red { background: #fef2f2; border: 1px solid #fecaca; border-radius: 8px; padding: 14px 18px; margin: 20px 0; color: #991b1b; font-size: 13px; }
+  .alert-amber { background: #fffbeb; border: 1px solid #fde68a; border-radius: 8px; padding: 14px 18px; margin: 20px 0; color: #92400e; font-size: 13px; }
+  .alert-green { background: #f0fdf4; border: 1px solid #bbf7d0; border-radius: 8px; padding: 14px 18px; margin: 20px 0; color: #14532d; font-size: 13px; }
+  .footer { background: #f8fafc; border-top: 1px solid #e2e8f0; padding: 20px 32px; text-align: center; color: #94a3b8; font-size: 12px; }
+  .footer a { color: #64748b; }
+</style>
+</head>
+<body>
+<div class="wrapper">
+  <div class="header">
+    <h1>TapTrack Hub</h1>
+    <p>Cloud Control Plane for TapTrack Deployments</p>
+  </div>
+  <div class="body">
+    {% block content %}{% endblock %}
+  </div>
+  <div class="footer">
+    <p>TapTrack Hub &nbsp;·&nbsp; <a href="mailto:support@taptrack.io">support@taptrack.io</a></p>
+    <p style="margin-top:4px">You are receiving this email because you are registered as a school administrator.</p>
+  </div>
+</div>
+</body>
+</html>

backend/app/templates/email/invoice.html

@@ -0,0 +1,20 @@
+{% extends "email/base.html" %}
+{% block content %}
+<h2>Invoice {{ invoice_number }}</h2>
+<p>Dear {{ contact_name }},</p>
+<p>Your invoice for <strong>{{ school_name }}</strong> has been generated for the period
+<strong>{{ period_start }}</strong> to <strong>{{ period_end }}</strong>.</p>
+
+<div class="info-box">
+  <div class="row"><span class="label">Invoice Number</span><span class="value">{{ invoice_number }}</span></div>
+  <div class="row"><span class="label">Billing Period</span><span class="value">{{ period_start }} — {{ period_end }}</span></div>
+  <div class="row"><span class="label">Amount Due</span><span class="value">PHP {{ amount }}</span></div>
+  <div class="row"><span class="label">Due Date</span><span class="value">{{ due_date }}</span></div>
+</div>
+
+<p>Please log in to your school portal to view and download your invoice.</p>
+<p><a class="btn" href="{{ portal_url }}/portal/billing">View Invoice</a></p>
+
+<p>If you have any questions, please contact us at <a href="mailto:support@taptrack.io">support@taptrack.io</a>.</p>
+<p>Thank you,<br><strong>TapTrack Hub Team</strong></p>
+{% endblock %}

backend/app/templates/email/license_expiry.html

@@ -0,0 +1,23 @@
+{% extends "email/base.html" %}
+{% block content %}
+<h2>License Expiring in {{ days_left }} Days</h2>
+<p>Dear {{ contact_name }},</p>
+
+<div class="alert-amber">
+  <strong>Your TapTrack license for {{ school_name }} expires on {{ expires_at }}.</strong>
+</div>
+
+<div class="info-box">
+  <div class="row"><span class="label">School</span><span class="value">{{ school_name }}</span></div>
+  <div class="row"><span class="label">License Key</span><span class="value" style="font-family:monospace;font-size:12px">{{ license_key }}</span></div>
+  <div class="row"><span class="label">Expires On</span><span class="value">{{ expires_at }}</span></div>
+  <div class="row"><span class="label">Days Remaining</span><span class="value" style="color:#b45309">{{ days_left }} days</span></div>
+</div>
+
+<p>When your license expires, SMS notifications will be disabled and your on-prem TapTrack
+instance will enter read-only mode. Please contact us to renew your license before it expires.</p>
+
+<p><a class="btn" href="mailto:support@taptrack.io?subject=License Renewal — {{ school_name }}">Contact Us to Renew</a></p>
+
+<p>Thank you,<br><strong>TapTrack Hub Team</strong></p>
+{% endblock %}

backend/app/templates/email/low_credit.html

@@ -0,0 +1,23 @@
+{% extends "email/base.html" %}
+{% block content %}
+<h2>Low SMS Credits — Action Required</h2>
+<p>Dear {{ contact_name }},</p>
+
+<div class="alert-amber">
+  <strong>Your SMS credit balance for {{ school_name }} is running low.</strong>
+</div>
+
+<div class="info-box">
+  <div class="row"><span class="label">School</span><span class="value">{{ school_name }}</span></div>
+  <div class="row"><span class="label">Current Balance</span><span class="value" style="color:#b45309">{{ credits_remaining }} credits</span></div>
+  <div class="row"><span class="label">Low Credit Threshold</span><span class="value">{{ threshold }} credits</span></div>
+</div>
+
+<p>SMS notifications to parents and guardians will stop working when your credit balance reaches zero.
+Please top up your credits to ensure uninterrupted service.</p>
+
+<p><a class="btn" href="{{ portal_url }}/portal/billing">Request Credit Top-Up</a></p>
+
+<p>If you need assistance, contact us at <a href="mailto:support@taptrack.io">support@taptrack.io</a>.</p>
+<p>Thank you,<br><strong>TapTrack Hub Team</strong></p>
+{% endblock %}

backend/app/templates/email/overdue_warning.html

@@ -0,0 +1,26 @@
+{% extends "email/base.html" %}
+{% block content %}
+<h2>Overdue Invoice — Immediate Action Required</h2>
+<p>Dear {{ contact_name }},</p>
+
+<div class="alert-red">
+  <strong>Invoice {{ invoice_number }} is overdue. Please settle this immediately to avoid account suspension.</strong>
+</div>
+
+<div class="info-box">
+  <div class="row"><span class="label">Invoice Number</span><span class="value">{{ invoice_number }}</span></div>
+  <div class="row"><span class="label">Amount</span><span class="value">PHP {{ amount }}</span></div>
+  <div class="row"><span class="label">Was Due On</span><span class="value" style="color:#dc2626">{{ due_date }}</span></div>
+  <div class="row"><span class="label">Days Overdue</span><span class="value" style="color:#dc2626">{{ days_overdue }} days</span></div>
+</div>
+
+<p>If this invoice is not settled within <strong>{{ days_until_suspension }} days</strong>, your TapTrack
+account will be automatically suspended. This will disable SMS notifications for your school.</p>
+
+<p><a class="btn" style="background:#dc2626" href="{{ portal_url }}/portal/billing">View &amp; Settle Invoice</a></p>
+
+<p>If you believe this is an error or need to discuss payment arrangements, please contact us
+at <a href="mailto:support@taptrack.io">support@taptrack.io</a> immediately.</p>
+
+<p>Thank you,<br><strong>TapTrack Hub Team</strong></p>
+{% endblock %}

backend/app/templates/email/suspension.html

@@ -0,0 +1,32 @@
+{% extends "email/base.html" %}
+{% block content %}
+<h2>Account Suspended</h2>
+<p>Dear {{ contact_name }},</p>
+
+<div class="alert-red">
+  <strong>Your TapTrack account for {{ school_name }} has been suspended due to an unpaid invoice.</strong>
+</div>
+
+<div class="info-box">
+  <div class="row"><span class="label">School</span><span class="value">{{ school_name }}</span></div>
+  <div class="row"><span class="label">Invoice</span><span class="value">{{ invoice_number }}</span></div>
+  <div class="row"><span class="label">Amount</span><span class="value">PHP {{ amount }}</span></div>
+  <div class="row"><span class="label">Original Due Date</span><span class="value">{{ due_date }}</span></div>
+</div>
+
+<p>The following services are now <strong>disabled</strong>:</p>
+<ul style="margin:8px 0 16px;padding-left:20px;color:#334155">
+  <li>SMS notifications to parents and guardians</li>
+  <li>Automated monthly reports</li>
+  <li>License validation (on-prem may enter warning mode)</li>
+</ul>
+
+<p>Attendance recording on your on-prem TapTrack instance continues to function.</p>
+
+<p>To restore full service, please settle the overdue invoice immediately and contact us at
+<a href="mailto:support@taptrack.io">support@taptrack.io</a> to lift the suspension.</p>
+
+<p><a class="btn" style="background:#dc2626" href="mailto:support@taptrack.io?subject=Account Suspension — {{ school_name }}">Contact Support to Restore</a></p>
+
+<p>Thank you,<br><strong>TapTrack Hub Team</strong></p>
+{% endblock %}