feat(rag): steering notes — tune how Brain answers, stored in Postgres and injected into every system prompt

alembic/versions/0003_steering_notes.py

@@ -0,0 +1,39 @@
+"""steering notes: owner tuning notes injected into every system prompt
+
+Revision ID: 0003
+Revises: 0002
+Create Date: 2026-08-22
+
+Phase 15 (steering-notes story): the owner can "tune" how Brain answers
+from the chat UI. Notes live in ``steering_notes`` and are read into the
+system prompt of every subsequent chat turn (``<tuning>`` section).
+"""
+from __future__ import annotations
+
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+from alembic import op
+
+revision = "0003"
+down_revision = "0002"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "steering_notes",
+        sa.Column("id", postgresql.UUID(as_uuid=True), primary_key=True),
+        sa.Column("note", sa.Text(), nullable=False),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.func.now(),
+            nullable=False,
+        ),
+    )
+
+
+def downgrade() -> None:
+    op.drop_table("steering_notes")