chore: scaffold monorepo and migrate uhd_web design system (W0-A)

- pnpm workspace: apps/{web,server}, packages/{contracts,db,domain,adapters,tasks,agent,testkit}
- server: Hono + zod-openapi, API Key auth with scopes, redacting pino logger, SSE event bus with replay, worker heartbeat
- db: Kysely + pg, file migrator, 0001_init (settings/api_key/audit_event/outbox_event)
- web: React Router 7 SPA console shell with 12 workspace placeholders, uhd_web tokens/ui/guard scripts
- docs: ADR-001 (Node over Deno), dev runbook, design system rules

Co-Authored-By: Claude Fable 5.1 <[email protected]>

packages/contracts/src/capability.ts

@@ -0,0 +1,45 @@
+import { z } from "zod";
+
+/**
+ * 能力调用上下文(REQ §10.3)。产品自有接口,不是 Pi SDK 原生 API。
+ * signal 由任务取消传播而来。
+ */
+export interface CapabilityContext {
+  actorId: string;
+  taskId: string;
+  scopeIds: string[];
+  signal: AbortSignal;
+}
+
+/** 变更计划:由业务端生成与保存,审批绑定 id + payloadHash + expectedRevision */
+export const MutationPlan = z.object({
+  id: z.string(),
+  operation: z.string(),
+  targetIds: z.array(z.string()),
+  expectedRevision: z.number().int().nonnegative(),
+  evidenceIds: z.array(z.string()),
+  payloadHash: z.string(),
+  requiresApproval: z.boolean(),
+});
+export type MutationPlan = z.infer<typeof MutationPlan>;
+
+/** 能力风险级别 */
+export const CapabilityRisk = z.enum(["read", "preview", "write", "destructive"]);
+export type CapabilityRisk = z.infer<typeof CapabilityRisk>;
+
+/** 能力 ID:`域.动作`,如 download.submit */
+export const CapabilityId = z.string().regex(/^[a-z][a-z0-9]*\.[a-z][a-z0-9_]*$/);
+export type CapabilityId = z.infer<typeof CapabilityId>;
+
+/** 能力定义(注册中心元数据;处理器在 server 侧挂载) */
+export interface CapabilityDefinition<I extends z.ZodType = z.ZodType, O extends z.ZodType = z.ZodType> {
+  id: CapabilityId;
+  version: number;
+  description: string;
+  input: I;
+  output: O;
+  scopes: string[];
+  risk: CapabilityRisk;
+  idempotent: boolean;
+  supportsPreview: boolean;
+}