Added Windsurf rule for Kanban

.windsurf/rules/kanban-sync.md

@@ -0,0 +1,20 @@
+---
+trigger: always_on
+---
+
+## Planka Sync
+
+**IMPORTANT**
+After completing any opsx workflow (/opsx:new, /opsx:ff, /opsx:continue,
+/opsx:apply, /opsx:verify, /opsx:archive, /opsx:bulk-archive), automatically
+reconcile Planka board state by running the sync script:
+
+```bash
+PROJECT_NAME=$(yq -r '.planka.project' project.yaml)
+BOARD_NAME=$(yq -r '.planka.board' project.yaml)
+kanban-project-sync --project "$PROJECT_NAME" --board "$BOARD_NAME" --background
+```
+
+The script handles concurrency (flock-based locking with coalescing pending queue).
+If the script is not on PATH or fails, log a brief warning and continue.
+Never block or retry — Planka sync is best-effort.