fix: correct CSS module import paths after file renames (Task 4.4)

- Fix incorrect relative paths in feature components after directory restructure
- Components in features/{domain}/ were importing ./features/{domain}/X.module.css
  instead of ./X.module.css
- Affected: AppShell, GitToolbar, FileEditor, CommitDialog, CommitPanel,
  MergeDialog, SettingsTabLayout, InstanceList, TerminalComponent

Quality gates: tsc (pass), eslint (pass), build (pass)
Refs: repo-restructure Task 4.4

apps/web/src/components/features/settings/SettingsTabLayout.tsx

@@ -1,6 +1,6 @@
 import React from "react";
 import { Link, useLocation } from "react-router-dom";
-import styles from "./features/settings/SettingsTabLayout.module.css";
+import styles from "./SettingsTabLayout.module.css";
 
 interface Tab {
 	id: string;