refactor: Migrate file-based data storage to database

web/db.py

@@ -51,3 +51,16 @@ class LogEntry(db.Model):
     timestamp = db.Column(db.DateTime, default=datetime.utcnow)
     phase = db.Column(db.String(50))
     message = db.Column(db.Text)
+
+
+class StoryState(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    project_id = db.Column(db.Integer, db.ForeignKey('project.id'), nullable=False)
+    state_json = db.Column(db.Text, nullable=True)
+    updated_at = db.Column(db.DateTime, default=datetime.utcnow)
+
+
+class Persona(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    name = db.Column(db.String(150), unique=True, nullable=False)
+    details_json = db.Column(db.Text, nullable=True)