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/number_ops/main.go

@@ -0,0 +1,100 @@
+// number_ops — 數字操作
+// 支援: round, floor, ceil, abs, add, subtract, multiply, divide, mod, min, max, format
+//
+//go:build tinygo
+
+package main
+
+import (
+	"encoding/json"
+	"io"
+	"math"
+	"os"
+	"strconv"
+)
+
+type Args struct {
+	Value    float64 `json:"value"`
+	Decimals int     `json:"decimals"`
+}
+
+type Input struct {
+	Operation string  `json:"operation"`
+	Input     float64 `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
+	}
+
+	var result interface{}
+
+	switch input.Operation {
+	case "round":
+		result = math.Round(input.Input)
+	case "floor":
+		result = math.Floor(input.Input)
+	case "ceil":
+		result = math.Ceil(input.Input)
+	case "abs":
+		result = math.Abs(input.Input)
+	case "add":
+		result = input.Input + input.Args.Value
+	case "subtract":
+		result = input.Input - input.Args.Value
+	case "multiply":
+		result = input.Input * input.Args.Value
+	case "divide":
+		if input.Args.Value == 0 {
+			writeError("除數不能為 0")
+			return
+		}
+		result = input.Input / input.Args.Value
+	case "mod":
+		if input.Args.Value == 0 {
+			writeError("除數不能為 0")
+			return
+		}
+		result = math.Mod(input.Input, input.Args.Value)
+	case "min":
+		result = math.Min(input.Input, input.Args.Value)
+	case "max":
+		result = math.Max(input.Input, input.Args.Value)
+	case "format":
+		decimals := input.Args.Decimals
+		if decimals < 0 {
+			decimals = 0
+		}
+		result = strconv.FormatFloat(input.Input, 'f', decimals, 64)
+	default:
+		writeError("不支援的 operation: " + input.Operation)
+		return
+	}
+
+	out, _ := json.Marshal(map[string]interface{}{
+		"success": true,
+		"data": map[string]interface{}{
+			"result":    result,
+			"operation": input.Operation,
+		},
+	})
+	os.Stdout.Write(out)
+}
+
+func writeError(msg string) {
+	out, _ := json.Marshal(map[string]interface{}{"success": false, "error": msg})
+	os.Stdout.Write(out)
+}