feat(arcrun): implement arcrun MVP — open-source AI workflow engine

Phase 1-5 complete per .agents/specs/u6u-core-mvp/:

**Phase 1 — Cherry-pick & cleanup**
- Create arcrun/ from cypher-executor, credentials, builtins, registry
- Remove 9 InkStone Service Bindings (KBDB, REGISTRY, CLINIC_*, AICEO, MINI_ME)
- Rewrite component-loader: 3-layer (builtin → WASM_BUCKET R2 → error)
- Remove autoPublishMissing.ts, proxy.ts (AICEO), execution-logger.ts (KBDB)
- Clean all KV namespace IDs and InkStone internal URLs from config files

**Phase 2 — contract.yaml completeness**
- Add credentials_required to gmail, google_sheets, telegram, line_notify
- Add config_example to all 21 components with annotated field descriptions

**Phase 3 — Credential injection**
- Add credential-injector.ts: AES-GCM decrypt from CREDENTIALS_KV
- Integrate into GraphExecutor before WASM execution
- Structured errors with repair instructions when credential missing

**Phase 4 — CLI (acr)**
- cli/package.json: arcrun package, bin: acr, deps: commander/js-yaml/chalk/ora
- 8 commands: init, creds push, push, run, validate, parts, list, logs
- Standard mode: writes directly to user's CF KV via CF REST API
- acr init: interactive setup with arcrun.dev API Key registration

**Phase 5 — Open source release prep**
- README.md: 5-minute quickstart, component table, workflow YAML syntax
- CONTRIBUTING.md: TinyGo dev env, component scaffolding, submission flow
- Security audit: no InkStone internal URLs/IDs in committed files
- .gitignore: exclude credentials.yaml, .wrangler, *.wasm

https://claude.ai/code/session_01BnCdSLVH8tUed9VrrPavgT

registry/src/types.ts

@@ -0,0 +1,99 @@
+// Component Registry Worker 型別定義
+
+import { z } from 'zod';
+
+// ── Cloudflare Bindings ──────────────────────────────────────────────────────
+
+export type Bindings = {
+  WASM_BUCKET: R2Bucket;
+  AI: Ai;
+  KBDB_URL: string;
+  KBDB_INTERNAL_TOKEN: string;
+  ENVIRONMENT: string;
+};
+
+// ── Component Contract Schema（Zod）─────────────────────────────────────────
+
+export const ConstraintsSchema = z.object({
+  max_size_kb: z.number().positive().max(2048),
+  max_cold_start_ms: z.number().positive().max(50),
+  no_network_syscall: z.boolean(),
+  io_model: z.literal('stdin_stdout_json'),
+});
+
+export const GherkinTestSchema = z.object({
+  scenario: z.string().min(1),
+  given: z.string().min(1),
+  then_contains: z.string().min(1),
+});
+
+export const ComponentContractSchema = z.object({
+  canonical_id: z.string().min(1).regex(/^[a-z][a-z0-9_]*$/, 'canonical_id 必須為小寫底線格式'),
+  display_name: z.string().min(1),
+  category: z.enum(['logic', 'api', 'ui', 'style', 'anim']),
+  version: z.string().min(1).regex(/^v\d+$/, 'version 格式必須為 vN'),
+  wasi_target: z.literal('preview1'),
+  stability: z.enum(['floating', 'stable', 'pinned']),
+  runtime_compat: z.array(z.enum(['cf-workers', 'workerd', 'wazero'])).min(1),
+  constraints: ConstraintsSchema,
+  input_schema: z.record(z.unknown()),
+  output_schema: z.record(z.unknown()),
+  gherkin_tests: z.array(GherkinTestSchema).min(2, '至少需要一個 happy path 和一個 error path'),
+  // 選填欄位
+  component_type: z.enum(['wasm', 'service_binding']).optional(),
+  max_size_kb: z.number().optional(),
+  max_cold_start_ms: z.number().optional(),
+  no_network_syscall: z.boolean().optional(),
+  service_binding_key: z.string().optional(),
+  description: z.string().optional(),
+  tags: z.array(z.string()).optional(),
+});
+
+export type ComponentContract = z.infer<typeof ComponentContractSchema>;
+
+// ── 沙盒驗收步驟 ─────────────────────────────────────────────────────────────
+
+export type SandboxStep = 'size_check' | 'cold_start' | 'syscall_scan' | 'gherkin_tests' | 'runtime_compat';
+
+export interface SandboxResult {
+  success: boolean;
+  failed_step?: SandboxStep;
+  reason?: string;
+  guide_anchor?: string;
+  component_id: string;
+  version: string;
+}
+
+// ── KBDB Block 格式 ──────────────────────────────────────────────────────────
+
+export interface KbdbBlock {
+  block_id: string;
+  template_id: string;
+  user_id?: string;
+  page_name?: string;
+}
+
+export interface KbdbSlots {
+  [key: string]: string;
+}
+
+// ── 禁止的 WASM syscall（網路 + 檔案系統）────────────────────────────────────
+
+export const FORBIDDEN_SYSCALLS = [
+  'sock_connect',
+  'sock_accept',
+  'sock_recv',
+  'sock_send',
+  'sock_shutdown',
+  'fd_open',
+  'path_open',
+  'path_create_directory',
+  'path_remove_directory',
+  'path_rename',
+  'path_unlink_file',
+  'path_filestat_get',
+  'path_filestat_set_times',
+  'path_link',
+  'path_readlink',
+  'path_symlink',
+] as const;