feat: add SSH key signing and verification UI

apps/web/src/api/ssh_keys.ts

@@ -24,3 +24,30 @@ export async function createSSHKey(data: SSHKeyCreate): Promise<SSHKey> {
 export async function deleteSSHKey(keyId: string): Promise<void> {
   await apiClient.delete(`/ssh-keys/${keyId}`);
 }
+
+export interface SignPayloadRequest {
+  payload: string;
+}
+
+export interface SignatureResponse {
+  signature: string;
+}
+
+export interface VerifySignatureRequest {
+  payload: string;
+  signature: string;
+}
+
+export interface VerifySignatureResponse {
+  valid: boolean;
+}
+
+export async function signPayload(keyId: string, data: SignPayloadRequest): Promise<SignatureResponse> {
+  const response = await apiClient.post<SignatureResponse>(`/ssh-keys/${keyId}/sign`, data);
+  return response.data;
+}
+
+export async function verifySignature(keyId: string, data: VerifySignatureRequest): Promise<VerifySignatureResponse> {
+  const response = await apiClient.post<VerifySignatureResponse>(`/ssh-keys/${keyId}/verify`, data);
+  return response.data;
+}