Frontend tests: migrate file browser, server form, server list, terminal and root-level tests to the shared api mock #908

Goal

The remaining test files use the shared createApiMock(); after this issue no test file in the frontend has a hand-written api factory.

Context

After the shared helpers exist (blocked-by issue), these files under apps/smart-ssh-community/frontend/src/ still have their own vi.mock("…/api", () => ({ … })) factory:

• components/FileBrowserPanel.test.tsx (≈ 3,400 lines), components/FileBrowserPanel.android.test.tsx, components/FileBrowserPanel.startDirectory.test.tsx
• components/ServerForm.test.tsx, ServerForm.android.test.tsx, ServerForm.extensionTabs.test.tsx, ServerForm.noPassword.test.tsx, ServerForm.startDirectory.test.tsx, ServerForm.tabs.test.tsx, ServerForm.testDialog.test.tsx, ServerForm.textCorrection.test.tsx
• components/ServerList.copyMarker.test.tsx, ServerList.narrow.test.tsx, ServerList.test.tsx
• components/TerminalView.keys.test.tsx, TerminalView.test.tsx
• App.hostKeyPrompt.test.tsx, treeDrag.test.ts, useLocalEditSession.test.ts, useSessionTabs.connect.test.ts, useSessionTabs.test.ts
• plus any file the previous migrations missed (grep -rlE 'vi\.mock\("(\.\./|\./|\.\./\.\./)api", *\(\) *=>' src).

Requirements

• Same as the previous migration: createApiMock({...overrides}), shared stubs into src/test/fixtures.ts, test cases unchanged.
• Add a guard test (src/test/noHandWrittenApiMock.test.ts) that fails when a test file defines a hand-written factory for the api module.

Acceptance Criteria

• The grep above returns nothing; the guard test passes and fails on a fixture string with a hand-written factory.
• Number of test cases per file unchanged (before/after list in the PR).
• npm test, npm run lint and the type-check pass.

Technical Notes

• Tests only. FileBrowserPanel.test.tsx and ServerForm*.test.tsx may be split by the component decomposition work at the same time; rebase rather than duplicate.

Spec impact: none

Related Work

• Blocked by Frontend tests: shared auto-mock for api.ts and renderChatPanel(); ChatPanel tests use them #906 (shared api mock).
• File browser: move the sub-components out of FileBrowserPanel.tsx into components/fileBrowser/ #819, File browser: extract FileTable, FileToolbar, TransferList and ElevationControls from FileBrowserPanel #821, File browser: extract useRemoteDirectory and useFileColumns hooks from FileBrowserPanel #824, File browser: extract useSftpTransfers and useElevation hooks from FileBrowserPanel #825, File browser: useFileOperations reducer for dialog state; FileBrowserPanel within the size limits #827 (file browser decomposition), Server form: extract useConnectionTest, useServerDelete and useIdentityFile hooks #857, Server form: useServerFormModel reducer for field values, loading and dirty tracking #861, Server form: separate LocalServerForm and RemoteServerForm with GeneralTab, ConnectionTab, SecurityTab and NotesTab #865 (server form decomposition) – they move tests; rebase onto them.