Add spin session functionality and update game mechanics

- Introduced a new `spin_sessions` table to track user spin activities.
- Updated the API to include a new endpoint for spinning games, allowing users to place bets and specify spin counts.
- Enhanced game information structure and added validation for bets and spin counts.
- Implemented the `Forest Fortune` slot game mechanics, including payline evaluation and scatter functionality.
- Updated dependencies in `pyproject.toml` for development and added `httpx` for HTTP requests.
- Added unit tests for the new slot mechanics and API endpoints to ensure functionality and reliability.

app/slots/registry.py

@@ -0,0 +1,29 @@
+from __future__ import annotations
+
+from app.slots.base import BaseSlot
+from app.slots.coming_soon import ComingSoonSlot
+from app.slots.forest_fortune import ForestFortuneSlot
+
+_SLOTS: list[BaseSlot] = [
+    ComingSoonSlot(
+        slug="raven-reels",
+        title="Вороньи Барабаны",
+        description="Слоты у врат Вырия. Скоро откроются.",
+    ),
+    ComingSoonSlot(
+        slug="golden-gate",
+        title="Золотые Врата",
+        description="Портал удачи. Пока запечатан.",
+    ),
+    ForestFortuneSlot(),
+]
+
+_BY_SLUG: dict[str, BaseSlot] = {slot.slug: slot for slot in _SLOTS}
+
+
+def list_slots() -> list[BaseSlot]:
+    return list(_SLOTS)
+
+
+def get_slot(slug: str) -> BaseSlot | None:
+    return _BY_SLUG.get(slug)