docs(registry): seed 10 examples + 5 skills (LI SDD M3.1 + M3.3)

對應 .agents/specs/llm-interface/ Milestone 3.1 + 3.3。

registry/examples/ — 10 個可直接 push 的 workflow 範本：
  starter:    webhook-to-http
  common:     cron-watcher, llm-classify, rag-search-answer, daily-digest
  external:   email-summary (gmail+claude+telegram), pdf-to-blocks,
              github-issue-bot
  advanced:   parallel-fanout (trigger_workflow fan-out),
              error-retry (try_catch+wait pattern)

  每個含：workflow.yaml（可直接 push）+ description.md（解決什麼問題 /
  改成你自己的 / 學到什麼）+ tags.json（搜尋用）

registry/skills/ — 5 個 AI playbook（markdown）：
  build_watcher_workflow            — cron + filter + trigger 模式
  debug_paused_workflow             — claude_api callback paused 怎麼追
  migrate_http_to_trigger_workflow  — 從 self-fetch 換 trigger_workflow
  rag_with_arcrun                   — KBDB + claude_api 組裝 RAG
  add_new_wasm_component            — TinyGo 寫 + 部署全流程

兩者差異：
  examples = 可直接拿來改的 YAML
  skills = 面對 X 問題該怎麼想 + 該用哪個 example

兩者後續：CI 自動同步進 KBDB（type=workflow-example / type=agent-skill），
MCP arcrun_search_examples / arcrun_list_skills 走 KBDB semantic search。
（CI sync 是 M3.4 工作）

Co-Authored-By: Claude Opus 4.7 <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}}"