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>

cypher-executor/src/routes/execute.ts

@@ -0,0 +1,56 @@
+import { Hono } from 'hono';
+import type { Bindings, ExecutionGraph } from '../types';
+import { ExecutionError } from '../types';
+import { GraphExecutor } from '../graph-executor';
+import { executeSchema } from '../lib/schemas';
+import { createComponentLoader } from '../lib/component-loader';
+import { writeExecutionVerdict } from '../actions/execution-logger';
+
+export const executeRouter = new Hono<{ Bindings: Bindings }>();
+
+// POST /execute — 執行一個完整的圖
+executeRouter.post('/execute', async (c) => {
+  const body = await c.req.json();
+  const parsed = executeSchema.safeParse(body);
+  if (!parsed.success) {
+    return c.json({ error: '圖定義驗證失敗', details: parsed.error.issues }, 400);
+  }
+
+  const { graph, context } = parsed.data;
+  const apiKey = c.req.header('x-arcrun-api-key') ?? undefined;
+  const loader = createComponentLoader(c.env);
+  const executor = new GraphExecutor(loader, undefined, c.env, apiKey);
+  const start = Date.now();
+
+  try {
+    // BUILD-006：傳入 KV namespace（若不存在則 fallback 到記憶體 merge）
+    const result = await executor.execute(graph as ExecutionGraph, context, c.env.EXEC_CONTEXT);
+    const duration_ms = Date.now() - start;
+    c.executionCtx.waitUntil(
+      writeExecutionVerdict(c.env, graph.id, graph.nodes, 'success', duration_ms, '執行完成')
+    );
+    return c.json({ success: true, data: result.data, trace: result.trace, duration_ms });
+  } catch (err) {
+    const duration_ms = Date.now() - start;
+    const errMsg = err instanceof Error ? err.message : String(err);
+    c.executionCtx.waitUntil(
+      writeExecutionVerdict(c.env, graph.id, graph.nodes, 'failed', duration_ms, errMsg.slice(0, 100))
+    );
+    if (err instanceof ExecutionError) {
+      const traceFormatted = err.trace.map(s => ({
+        node: s.nodeId,
+        status: s.error ? 'failed' : 'success',
+        ...(s.error ? { error: s.error } : {}),
+      }));
+      return c.json({
+        success: false,
+        error: errMsg,
+        failed_node: err.failed_node,
+        failed_input: err.failed_input,
+        trace: traceFormatted,
+        duration_ms,
+      }, 500);
+    }
+    return c.json({ success: false, error: errMsg, failed_node: null, trace: [], duration_ms }, 500);
+  }
+});