Implement FastAPI backend and Vue 3 frontend for Lowkey Backtest UI

- Added FastAPI backend with core API endpoints for strategies, backtests, and data management.
- Introduced Vue 3 frontend with a dark theme, enabling users to run backtests, adjust parameters, and compare results.
- Implemented Pydantic schemas for request/response validation and SQLAlchemy models for database interactions.
- Enhanced project structure with dedicated modules for services, routers, and components.
- Updated dependencies in `pyproject.toml` and `frontend/package.json` to include FastAPI, SQLAlchemy, and Vue-related packages.
- Improved `.gitignore` to exclude unnecessary files and directories.

api/routers/strategies.py

@@ -0,0 +1,67 @@
+"""
+Strategy information endpoints.
+"""
+from typing import Any
+
+import numpy as np
+from fastapi import APIRouter
+
+from api.models.schemas import StrategiesResponse, StrategyInfo
+from strategies.factory import get_registry
+
+router = APIRouter()
+
+
+def _serialize_param_value(value: Any) -> Any:
+    """Convert numpy arrays and other types to JSON-serializable format."""
+    if isinstance(value, np.ndarray):
+        return value.tolist()
+    if isinstance(value, (np.integer, np.floating)):
+        return value.item()
+    return value
+
+
+def _get_display_name(name: str) -> str:
+    """Convert strategy key to display name."""
+    display_names = {
+        "rsi": "RSI Strategy",
+        "macross": "MA Crossover",
+        "meta_st": "Meta Supertrend",
+        "regime": "Regime Reversion (ML)",
+    }
+    return display_names.get(name, name.replace("_", " ").title())
+
+
+@router.get("/strategies", response_model=StrategiesResponse)
+async def get_strategies():
+    """
+    Get list of available strategies with their parameters.
+    
+    Returns strategy names, default parameters, and grid search ranges.
+    """
+    registry = get_registry()
+    strategies = []
+    
+    for name, config in registry.items():
+        strategy_instance = config.strategy_class()
+        
+        # Serialize parameters (convert numpy arrays to lists)
+        default_params = {
+            k: _serialize_param_value(v) 
+            for k, v in config.default_params.items()
+        }
+        grid_params = {
+            k: _serialize_param_value(v) 
+            for k, v in config.grid_params.items()
+        }
+        
+        strategies.append(StrategyInfo(
+            name=name,
+            display_name=_get_display_name(name),
+            market_type=strategy_instance.default_market_type.value,
+            default_leverage=strategy_instance.default_leverage,
+            default_params=default_params,
+            grid_params=grid_params,
+        ))
+    
+    return StrategiesResponse(strategies=strategies)