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/components/date_ops/main.go

@@ -0,0 +1,103 @@
+// date_ops — 日期操作
+// 支援: now, format, parse
+// TinyGo time 套件支援有限，只實作基本功能
+//
+//go:build tinygo
+
+package main
+
+import (
+	"encoding/json"
+	"io"
+	"os"
+	"time"
+)
+
+type Args struct {
+	Layout string `json:"layout"`
+}
+
+type Input struct {
+	Operation string `json:"operation"`
+	Input     string `json:"input"`
+	Args      Args   `json:"args"`
+}
+
+func main() {
+	raw, err := io.ReadAll(os.Stdin)
+	if err != nil {
+		writeError("failed to read stdin: " + err.Error())
+		return
+	}
+	var input Input
+	if err := json.Unmarshal(raw, &input); err != nil {
+		writeError("invalid input JSON: " + err.Error())
+		return
+	}
+	if input.Operation == "" {
+		writeError("operation 必填")
+		return
+	}
+
+	switch input.Operation {
+	case "now":
+		result := time.Now().UTC().Format(time.RFC3339)
+		writeResult("now", result)
+	case "format":
+		if input.Input == "" {
+			writeError("format 需要 input 日期字串")
+			return
+		}
+		t, err := time.Parse(time.RFC3339, input.Input)
+		if err != nil {
+			// 嘗試其他格式
+			t, err = time.Parse("2006-01-02", input.Input)
+			if err != nil {
+				writeError("無法解析日期: " + err.Error())
+				return
+			}
+		}
+		layout := input.Args.Layout
+		if layout == "" {
+			layout = time.RFC3339
+		}
+		writeResult("format", t.Format(layout))
+	case "parse":
+		if input.Input == "" {
+			writeError("parse 需要 input 日期字串")
+			return
+		}
+		t, err := time.Parse(time.RFC3339, input.Input)
+		if err != nil {
+			t, err = time.Parse("2006-01-02", input.Input)
+			if err != nil {
+				writeError("無法解析日期: " + err.Error())
+				return
+			}
+		}
+		writeResult("parse", map[string]interface{}{
+			"iso":   t.UTC().Format(time.RFC3339),
+			"year":  t.Year(),
+			"month": int(t.Month()),
+			"day":   t.Day(),
+			"hour":  t.Hour(),
+			"min":   t.Minute(),
+			"sec":   t.Second(),
+		})
+	default:
+		writeError("不支援的 operation: " + input.Operation)
+	}
+}
+
+func writeResult(op string, result interface{}) {
+	out, _ := json.Marshal(map[string]interface{}{
+		"success": true,
+		"data":    map[string]interface{}{"result": result, "operation": op},
+	})
+	os.Stdout.Write(out)
+}
+
+func writeError(msg string) {
+	out, _ := json.Marshal(map[string]interface{}{"success": false, "error": msg})
+	os.Stdout.Write(out)
+}