Update settings/admin UI and misc fixes

app/models.py

@@ -115,3 +115,38 @@ class DisplaySession(db.Model):
     display = db.relationship("Display")
 
     __table_args__ = (db.UniqueConstraint("display_id", "sid", name="uq_display_session_display_sid"),)
+
+
+class AppSettings(db.Model):
+    """Singleton-ish app-wide settings.
+
+    For this small project we avoid Alembic migrations; this table can be created via
+    `flask init-db` (db.create_all) and is also created best-effort on app startup.
+
+    NOTE: SMTP password is stored in plaintext in the database.
+    Prefer environment variables / secrets management in production when possible.
+    """
+
+    id = db.Column(db.Integer, primary_key=True)
+
+    smtp_host = db.Column(db.String(255), nullable=True)
+    smtp_port = db.Column(db.Integer, nullable=True)
+    smtp_username = db.Column(db.String(255), nullable=True)
+    smtp_password = db.Column(db.String(255), nullable=True)
+    smtp_from = db.Column(db.String(255), nullable=True)
+
+    smtp_starttls = db.Column(db.Boolean, default=True, nullable=False)
+    smtp_timeout_seconds = db.Column(db.Float, default=10.0, nullable=False)
+    smtp_debug = db.Column(db.Boolean, default=False, nullable=False)
+
+    # Public domain for generating absolute links in emails.
+    # Example: "signage.example.com" (no scheme)
+    public_domain = db.Column(db.String(255), nullable=True)
+
+    created_at = db.Column(db.DateTime, default=datetime.utcnow, nullable=False)
+    updated_at = db.Column(
+        db.DateTime,
+        default=datetime.utcnow,
+        onupdate=datetime.utcnow,
+        nullable=False,
+    )