fix: add missing columns migration (signal, ai_reasoning, leverage, etc.)

- posts: signal, ai_reasoning, prefilter_reason, analysis_version
- subscriptions: leverage, position_size_usd, take_profit_pct, stop_loss_pct, min_confidence

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

alembic/versions/002_add_missing_columns.py

@@ -0,0 +1,47 @@
+"""Add missing columns to posts and subscriptions
+
+Revision ID: 002
+Revises: 001
+Create Date: 2026-04-21 00:00:00.000000
+"""
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "002"
+down_revision: Union[str, None] = "001"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # ── posts: missing columns ────────────────────────────────────────────────
+    with op.batch_alter_table("posts") as batch_op:
+        batch_op.add_column(sa.Column("signal", sa.String(8), nullable=True))
+        batch_op.add_column(sa.Column("ai_reasoning", sa.Text(), nullable=True))
+        batch_op.add_column(sa.Column("prefilter_reason", sa.String(32), nullable=True))
+        batch_op.add_column(sa.Column("analysis_version", sa.String(16), nullable=True))
+
+    # ── subscriptions: per-user trading config ────────────────────────────────
+    with op.batch_alter_table("subscriptions") as batch_op:
+        batch_op.add_column(sa.Column("leverage", sa.Integer(), nullable=False, server_default="3"))
+        batch_op.add_column(sa.Column("position_size_usd", sa.Float(), nullable=False, server_default="20.0"))
+        batch_op.add_column(sa.Column("take_profit_pct", sa.Float(), nullable=True))
+        batch_op.add_column(sa.Column("stop_loss_pct", sa.Float(), nullable=True))
+        batch_op.add_column(sa.Column("min_confidence", sa.Integer(), nullable=False, server_default="80"))
+
+
+def downgrade() -> None:
+    with op.batch_alter_table("subscriptions") as batch_op:
+        batch_op.drop_column("min_confidence")
+        batch_op.drop_column("stop_loss_pct")
+        batch_op.drop_column("take_profit_pct")
+        batch_op.drop_column("position_size_usd")
+        batch_op.drop_column("leverage")
+
+    with op.batch_alter_table("posts") as batch_op:
+        batch_op.drop_column("analysis_version")
+        batch_op.drop_column("prefilter_reason")
+        batch_op.drop_column("ai_reasoning")
+        batch_op.drop_column("signal")