feat: project foundation — monorepo setup, shared config, redis streams, telemetry

- pyproject.toml with core deps and optional dep groups per service
- shared/config.py: Pydantic BaseSettings with TRADING_ env prefix
- shared/redis_streams.py: StreamPublisher/StreamConsumer wrappers
- shared/telemetry.py: OpenTelemetry + Prometheus metric export
- tests for Redis Streams helpers (5 passing)

shared/config.py

@@ -0,0 +1,19 @@
+"""Shared configuration for all trading bot services."""
+
+from pydantic_settings import BaseSettings
+
+
+class BaseConfig(BaseSettings):
+    """Base configuration shared across all services.
+
+    All settings can be overridden via environment variables
+    prefixed with ``TRADING_``.
+    """
+
+    database_url: str = "postgresql+asyncpg://trading:trading@localhost:5432/trading"
+    redis_url: str = "redis://localhost:6379/0"
+    log_level: str = "INFO"
+    otel_service_name: str = "trading-bot"
+    otel_metrics_port: int = 9090
+
+    model_config = {"env_prefix": "TRADING_"}