refactor(scoring): persist weights in DB table, replace mutable Settings with scoring_config_service

backend/alembic/versions/b027_add_scoring_config.py

@@ -0,0 +1,37 @@
+"""add_scoring_config
+
+Single-row table to persist scoring weights in the database,
+replacing the mutable in-process Settings approach.
+
+Revision ID: b027scorecfg
+Revises: b026techidx
+Create Date: 2026-02-19 10:00:00.000000
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+revision: str = "b027scorecfg"
+down_revision: Union[str, None] = "b026techidx"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "scoring_config",
+        sa.Column("id", postgresql.UUID(as_uuid=True), primary_key=True),
+        sa.Column("weight_tests", sa.Float(), nullable=False, server_default="40.0"),
+        sa.Column("weight_detection_rules", sa.Float(), nullable=False, server_default="20.0"),
+        sa.Column("weight_d3fend", sa.Float(), nullable=False, server_default="15.0"),
+        sa.Column("weight_freshness", sa.Float(), nullable=False, server_default="15.0"),
+        sa.Column("weight_platform_diversity", sa.Float(), nullable=False, server_default="10.0"),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now()),
+    )
+
+
+def downgrade() -> None:
+    op.drop_table("scoring_config")