Add waiting system application files

- Add main application files (main.py, models.py, schemas.py, etc.)
- Add routers for all features (waiting, attendance, members, etc.)
- Add HTML templates for admin and user interfaces
- Add migration scripts and utility files
- Add Docker configuration
- Add documentation files
- Add .gitignore to exclude database and cache files

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

schemas_next_slot.py

@@ -0,0 +1,10 @@
+
+from pydantic import BaseModel
+
+class NextSlotResponse(BaseModel):
+    class_id: int
+    class_name: str
+    class_order: int
+    max_capacity: int
+    is_full: bool
+    total_waiting: int # For the store