feat(RMGR-WP-0003): production pilot dual-run config, bulk, push

Config file dual-run (env override), writeback_push, bulk-status facade
on State Hub, pilot example config, evidence and finished workplan.

config/dual-run.pilot.example.yaml

@@ -0,0 +1,10 @@
+# Example dual-run pilot config (RMGR-WP-0003).
+# Install: cp config/dual-run.pilot.example.yaml ~/.repo-manager/dual-run.yaml
+# Env vars still override when set. Rollback: writeback/reconcile false or delete file.
+
+writeback: true
+reconcile: true
+writeback_push: false   # set true only if pilot checkouts can push safely
+pilot_repos:
+  - repo-manager
+meter_path: ~/.repo-manager/mutation-meter.jsonl