Add safe schema patches for MVP database updates

app/db.py

@@ -1,5 +1,5 @@
 from collections.abc import Generator
-from sqlalchemy import create_engine
+from sqlalchemy import create_engine, inspect, text
 from sqlalchemy.orm import DeclarativeBase, Session, sessionmaker
 
 from app.core import get_settings
@@ -25,3 +25,36 @@ def init_db() -> None:
     from app import models  # noqa: F401
 
     Base.metadata.create_all(bind=engine)
+    apply_safe_schema_patches()
+
+
+def apply_safe_schema_patches() -> None:
+    """Tiny compatibility layer for the early MVP.
+
+    SQLAlchemy create_all creates missing tables but does not alter existing ones.
+    During rapid MVP iterations this keeps old server databases from breaking
+    when a new column is added.
+    """
+    inspector = inspect(engine)
+    if 'bot_state' in inspector.get_table_names():
+        existing = {column['name'] for column in inspector.get_columns('bot_state')}
+        patches = []
+        if 'live_acknowledged' not in existing:
+            patches.append("ALTER TABLE bot_state ADD COLUMN live_acknowledged BOOLEAN NOT NULL DEFAULT FALSE")
+        if 'emergency_stop' not in existing:
+            patches.append("ALTER TABLE bot_state ADD COLUMN emergency_stop BOOLEAN NOT NULL DEFAULT FALSE")
+        if 'trade_mode' not in existing:
+            patches.append("ALTER TABLE bot_state ADD COLUMN trade_mode VARCHAR(16) NOT NULL DEFAULT 'demo'")
+        if 'enabled' not in existing:
+            patches.append("ALTER TABLE bot_state ADD COLUMN enabled BOOLEAN NOT NULL DEFAULT FALSE")
+        if 'trade_style_mode' not in existing:
+            patches.append("ALTER TABLE bot_state ADD COLUMN trade_style_mode VARCHAR(32) NOT NULL DEFAULT 'balanced'")
+        if 'min_signal_score' not in existing:
+            patches.append("ALTER TABLE bot_state ADD COLUMN min_signal_score FLOAT NOT NULL DEFAULT 65.0")
+        if 'max_open_positions' not in existing:
+            patches.append("ALTER TABLE bot_state ADD COLUMN max_open_positions INTEGER NOT NULL DEFAULT 3")
+        if 'max_quote_per_trade' not in existing:
+            patches.append("ALTER TABLE bot_state ADD COLUMN max_quote_per_trade FLOAT NOT NULL DEFAULT 100.0")
+        with engine.begin() as conn:
+            for patch in patches:
+                conn.execute(text(patch))