refactor: rename frontend API files to kebab-case

Renamed:
- git_repositories.ts → git-repositories.ts
- ssh_keys.ts → ssh-keys.ts
- tool_types.ts → tool-types.ts
- tool_types.test.ts → tool-types.test.ts

Updated all imports across components, pages, and hooks.

Quality gates: verified no remaining old imports.

apps/web/src/api/ssh-keys.ts

@@ -0,0 +1,53 @@
+import { apiClient } from "./client";
+
+export interface SSHKey {
+  id: string;
+  name: string;
+  public_key: string;
+  created_at: string;
+}
+
+export interface SSHKeyCreate {
+  name: string;
+}
+
+export async function listSSHKeys(): Promise<SSHKey[]> {
+  const response = await apiClient.get<SSHKey[]>("/ssh-keys");
+  return response.data;
+}
+
+export async function createSSHKey(data: SSHKeyCreate): Promise<SSHKey> {
+  const response = await apiClient.post<SSHKey>("/ssh-keys", data);
+  return response.data;
+}
+
+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;
+}