feat: organize news packages into verified event timelines

Add optional events, evidence-backed timelines, versioned package corrections and bounded historical reprocessing. Keep independent packages readable and isolate retries by failed stage. Configure reasoning effort per model stage and refresh default news Skill drafts without publishing.

backend/alembic/versions/20261101_c3d5e7f90123_news_reasoning_effort.py

@@ -0,0 +1,18 @@
+"""Add independent reasoning effort overrides for news stages."""
+from alembic import op
+import sqlalchemy as sa
+
+revision = 'c3d5e7f90123'
+down_revision = 'b2c4d6e8f012'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    for column in ('reasoning_effort', 'second_reasoning_effort', 'third_reasoning_effort'):
+        op.add_column('risk_settings', sa.Column(column, sa.String(16), nullable=True))
+
+
+def downgrade():
+    for column in ('third_reasoning_effort', 'second_reasoning_effort', 'reasoning_effort'):
+        op.drop_column('risk_settings', column)