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/hooks/use-git-repo.ts

@@ -21,7 +21,7 @@ import {
 	type Branch,
 	type CommitHistoryResponse,
 	type CommitDetail,
-} from "../api/git_repositories";
+} from "../api/git-repositories";
 
 export interface GitStatus {
 	branch: string;