feat: add SQLAlchemy ORM models and Alembic migration setup

Add SA 2.0 declarative models (CandleRow, SignalRow, OrderRow, TradeRow,
PositionRow, PortfolioSnapshotRow) mirroring existing asyncpg tables.
Set up Alembic with async PostgreSQL support and add migrate/migrate-down/
migrate-new Makefile targets. Update shared dependencies with sqlalchemy,
alembic, structlog, prometheus-client, pyyaml, aiohttp, and rich.

1 files changed, 26 insertions, 0 deletions

diff --git a/shared/alembic/script.py.mako b/shared/alembic/script.py.mako
new file mode 100644
index 0000000..fbc4b07
--- /dev/null
+++ b/shared/alembic/script.py.mako
@@ -0,0 +1,26 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision: str = ${repr(up_revision)}
+down_revision: Union[str, None] = ${repr(down_revision)}
+branch_labels: Union[str, Sequence[str], None] = ${repr(branch_labels)}
+depends_on: Union[str, Sequence[str], None] = ${repr(depends_on)}
+
+
+def upgrade() -> None:
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    ${downgrades if downgrades else "pass"}