feat!: genesis-pinned operator set, server identity with an encrypted control link, key-less join codes; release key continuity

Join codes need no passkey touch and carry only public values (genesis
fingerprint, owner credentials, installer hashes). Nodes pin the genesis and
owners at enrollment and only follow passkey-signed operator set versions.
The panel's server key is listed in the set; pinned nodes require its
signature and run the control link under AES-256-GCM. Password sessions carry
no capabilities. The updater adopts a next_key from a signed manifest.

Bump version to 0.2.0. [CI SKIP]

web/shared/api/webauthn.ts

@@ -1,5 +1,5 @@
 import { api } from './client'
-import type { LoginResponse, PasskeyCreationOptionsDto, PasskeyDto, PasskeyRequestOptionsDto } from './types'
+import type { LoginResponse, PasskeyCreationOptionsDto, PasskeyDto, PasskeyRequestOptionsDto, SignedStatementDto } from './types'
 
 /** 浏览器是否支持在输入框的自动填充里列出 passkey（conditional UI）。 */
 export async function conditionalSupported(): Promise<boolean> {
@@ -58,6 +58,30 @@ export async function signInWithPasskey(opts: { conditional?: boolean; signal?:
   })
 }
 
+/**
+ * 用 passkey 对一段文本签名（挑战是文本的 SHA-256）：操作员集合、加入码的委托都是这样签出来的，节点自己验。
+ * 浏览器会让用户从这个站点的 passkey 里选一个；面板再检查它是不是操作员集合里的凭证。
+ */
+export async function signStatement(statement: string): Promise<SignedStatementDto> {
+  const challenge = new Uint8Array(await crypto.subtle.digest('SHA-256', new TextEncoder().encode(statement)))
+  let credential: PublicKeyCredential | null
+  try {
+    credential = (await navigator.credentials.get({ publicKey: { challenge, userVerification: 'required', timeout: 120_000 } })) as PublicKeyCredential | null
+  } catch (e) {
+    if (e instanceof DOMException && (e.name === 'NotAllowedError' || e.name === 'AbortError')) throw new Error('已取消')
+    throw e
+  }
+  if (!credential) throw new Error('没有选择 passkey')
+  const response = credential.response as AuthenticatorAssertionResponse
+  return {
+    statement,
+    credential_id: credential.id,
+    authenticator_data: toText(response.authenticatorData),
+    client_data_json: toText(response.clientDataJSON),
+    signature: toText(response.signature),
+  }
+}
+
 /** 提权窗口的种类：加节点、吊销和删除、改凭证（用一次就没有）。 */
 export type ElevationClass = 'enroll' | 'revoke' | 'credential'