feat: full integration — app.py wiring, scheduler startup, route registration, README

- Wire blueprints and scheduler into create_app()
- Add start_scheduler param to skip scheduler in tests
- Fix Setting.get/set to use modern db.session.get()
- Remove unused imports from conftest and models
- Add README with quick start and usage guide

Made-with: Cursor

src/models.py

@@ -1,5 +1,5 @@
 import json
-from datetime import datetime, date, timezone
+from datetime import datetime, timezone
 from app import db
 
 
@@ -58,14 +58,14 @@ class Setting(db.Model):
 
     @staticmethod
     def get(key, default=None):
-        row = Setting.query.get(key)
+        row = db.session.get(Setting, key)
         if row is None:
             return default
         return json.loads(row.value)
 
     @staticmethod
     def set(key, value):
-        row = Setting.query.get(key)
+        row = db.session.get(Setting, key)
         if row is None:
             row = Setting(key=key, value=json.dumps(value))
             db.session.add(row)