06/05 Optimize app

app/models/teller_enrollment.py

@@ -52,3 +52,25 @@ class TellerAccount(db.Model):
 
     def __repr__(self):
         return f'<TellerAccount {self.account_name} → PFM #{self.pfm_account_id}>'
+
+
+class TellerSyncPreview(db.Model):
+    """
+    Temporary server-side storage for sync preview data.
+    Replaces cookie-based session storage which has a 4 KB limit —
+    large accounts (100+ transactions) exceeded that limit and caused
+    silent data loss on the confirm step.
+    One row per teller_account_id; overwritten on each new sync preview.
+    """
+    __tablename__ = 'teller_sync_previews'
+
+    id              = db.Column(db.Integer, primary_key=True)
+    teller_account_id = db.Column(
+        db.Integer, db.ForeignKey('teller_accounts.id'),
+        nullable=False, unique=True, index=True,
+    )
+    data_json       = db.Column(db.Text, nullable=False)
+    created_at      = db.Column(db.DateTime, default=datetime.utcnow)
+
+    def __repr__(self):
+        return f'<TellerSyncPreview account_id={self.teller_account_id}>'