arcrun — AI workflow execution engine (clean history)

Self-hosted 開源：WASM 零件 + recipe + cypher-executor，跑在你自己的 Cloudflare。

此為重建的乾淨歷史起點（移除曾誤 commit 的 GCP SA 金鑰，舊歷史保留在
richblack/arcrun 與本地 backup 分支）。含：
- acr init --self-hosted installer（建 KV/R2 + codeload 拉預編譯 wasm + wrangler deploy + seed recipe）
- recipe push 把關（資料外流提醒 + 打通檢查）
- 19 個正當零件預編譯 wasm（claude_api/km_writer/kbdb_upsert_block 排除：違反 DECISIONS §1）
- CLI / cypher-executor / registry / 完整 SDD

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

registry/examples/cron-watcher/workflow.yaml

@@ -0,0 +1,38 @@
+name: cron_watcher_example
+description: 每 5 分鐘掃 KBDB 未處理的 note → 對每筆觸發子 workflow
+
+flow:
+  - "watch_cron >> ON_SUCCESS >> list_unprocessed"
+  - "list_unprocessed >> ON_SUCCESS >> filter_new"
+  - "filter_new >> 對每個 item >> trigger_processor"
+
+config:
+  watch_cron:
+    component: cron
+    cron_expr: "*/5 * * * *"
+    description: "每 5 分鐘掃一次"
+
+  list_unprocessed:
+    component: kbdb_get
+    api_key: "{{api_key}}"
+    type: "note"
+    source: "user-input"
+    limit: 20
+
+  filter_new:
+    component: filter
+    items: "{{list_unprocessed.blocks}}"
+    condition:
+      key: "tags_json"
+      op: "eq"
+      value: "[]"
+
+  # trigger_workflow 是內建 orchestration 零件，in-process call 另一個 workflow
+  # **千萬不要用 http_request 自打 cypher-executor 自己的 webhook** — 會撞 CF self-fetch 死鎖
+  trigger_processor:
+    component: trigger_workflow
+    workflow_name: "your_processor_workflow"   # ← 改成你的處理 workflow 名
+    api_key: "{{api_key}}"
+    input:
+      api_key: "{{api_key}}"
+      block_id: "{{item.id}}"