feat: derive POSTGRES_DB and Redis prefix from DEPLOY_STAGE for pipeline isolation

services/shared/config.py

@@ -105,6 +105,12 @@ def _bucket(name: str) -> str:
     prefix = os.getenv("DEPLOY_STAGE", "")
     return f"{prefix}-{name}" if prefix else name
 
+
+def _stage_db() -> str:
+    """Derive database name from DEPLOY_STAGE. Empty stage = 'stonks'."""
+    stage = os.getenv("DEPLOY_STAGE", "")
+    return f"stonks_{stage}" if stage else "stonks"
+
 BUCKET_RETENTION_FIELDS: dict[str, str] = {
     _bucket("stonks-raw-market"): "raw_market_days",
     _bucket("stonks-raw-news"): "raw_news_days",
@@ -229,7 +235,7 @@ def load_config() -> AppConfig:
         postgres=PostgresConfig(
             host=os.getenv("POSTGRES_HOST", "localhost"),
             port=int(os.getenv("POSTGRES_PORT", "5432")),
-            database=os.getenv("POSTGRES_DB", "stonks"),
+            database=os.getenv("POSTGRES_DB", "") or _stage_db(),
             user=os.getenv("POSTGRES_USER", "stonks"),
             password=os.getenv("POSTGRES_PASSWORD", "stonks_dev"),
         ),