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/github-issue-bot/workflow.yaml

@@ -0,0 +1,51 @@
+name: github_issue_bot
+description: GH webhook 收新 issue → claude 分析 → 自動留 comment + 加 label
+
+flow:
+  - "input >> ON_SUCCESS >> analyze"
+  - "analyze >> ON_SUCCESS >> add_comment"
+  - "add_comment >> ON_SUCCESS >> add_labels"
+
+config:
+  analyze:
+    component: claude_api
+    timeout_ms: 30000
+    _recipe_output_format: json
+    _recipe_output_required_fields:
+      - severity
+      - category
+      - first_response
+    prompt: |
+      你是 GitHub issue 第一線分流員。對下列 issue 給出：
+      - severity: "critical" | "high" | "medium" | "low"
+      - category: "bug" | "feature" | "doc" | "question" | "other"
+      - first_response: 一段 markdown，禮貌、有用、不假裝是真人
+
+      若是 bug，guide 用戶提供 reproduce steps；若 question 直接回答；
+      若 feature 引導去 discussion；若 doc 直接收。
+
+      Issue:
+      Title: {{input.issue.title}}
+      Body: {{input.issue.body}}
+
+  add_comment:
+    component: http_request
+    url: "https://api.github.com/repos/{{input.repository.full_name}}/issues/{{input.issue.number}}/comments"
+    method: POST
+    headers:
+      Authorization: "Bearer {{secret.GITHUB_BOT_TOKEN}}"
+      Accept: "application/vnd.github+json"
+    body_json:
+      body: "{{analyze.first_response}}"
+
+  add_labels:
+    component: http_request
+    url: "https://api.github.com/repos/{{input.repository.full_name}}/issues/{{input.issue.number}}/labels"
+    method: POST
+    headers:
+      Authorization: "Bearer {{secret.GITHUB_BOT_TOKEN}}"
+    body_json:
+      labels:
+        - "auto-triaged"
+        - "severity:{{analyze.severity}}"
+        - "type:{{analyze.category}}"