feat: traefik plugin migration (traefik_001_initial, depends_on core head)

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

plugins/traefik/migrations/versions/traefik_001_initial.py

@@ -0,0 +1,37 @@
+# plugins/traefik/migrations/versions/traefik_001_initial.py
+"""Traefik metrics table
+
+Revision ID: traefik_001_initial
+Revises: (none — this is a branch off the core head via depends_on)
+Create Date: 2026-03-17
+"""
+from typing import Sequence, Union
+from alembic import op
+import sqlalchemy as sa
+
+revision: str = "traefik_001_initial"
+down_revision: Union[str, None] = None
+branch_labels: Union[str, Sequence[str], None] = "traefik"
+depends_on: Union[str, Sequence[str], None] = ("0003_ansible_runs",)
+
+
+def upgrade() -> None:
+    op.create_table(
+        "traefik_metrics",
+        sa.Column("id", sa.String(36), primary_key=True),
+        sa.Column("router_name", sa.String(255), nullable=False),
+        sa.Column("scraped_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("request_rate", sa.Float, nullable=False),
+        sa.Column("error_rate_4xx_pct", sa.Float, nullable=False),
+        sa.Column("error_rate_5xx_pct", sa.Float, nullable=False),
+        sa.Column("latency_p50_ms", sa.Float, nullable=False),
+        sa.Column("latency_p95_ms", sa.Float, nullable=False),
+        sa.Column("latency_p99_ms", sa.Float, nullable=False),
+    )
+    op.create_index("ix_traefik_metrics_router_scraped", "traefik_metrics",
+                    ["router_name", "scraped_at"])
+
+
+def downgrade() -> None:
+    op.drop_index("ix_traefik_metrics_router_scraped", "traefik_metrics")
+    op.drop_table("traefik_metrics")