refactor(wizard): rebuild project creation flow as modular TypeScript components

Replace the monolithic `ProjectCreationWizard.jsx` with a feature-based TS
implementation under `src/components/project-creation-wizard`, while preserving
existing behavior and improving readability, maintainability, and state isolation.

Why:
- The previous wizard mixed API logic, flow state, folder browsing, and UI in one file.
- Refactoring and testing were difficult due to tightly coupled concerns.
- We needed stronger type safety and localized component state.

What changed:
- Deleted:
  - `src/components/ProjectCreationWizard.jsx`
- Added new modular structure:
  - `src/components/project-creation-wizard/index.ts`
  - `src/components/project-creation-wizard/ProjectCreationWizard.tsx`
  - `src/components/project-creation-wizard/types.ts`
  - `src/components/project-creation-wizard/data/workspaceApi.ts`
  - `src/components/project-creation-wizard/hooks/useGithubTokens.ts`
  - `src/components/project-creation-wizard/utils/pathUtils.ts`
  - `src/components/project-creation-wizard/components/*`
    - `WizardProgress`, `WizardFooter`, `ErrorBanner`
    - `StepTypeSelection`, `StepConfiguration`, `StepReview`
    - `WorkspacePathField`, `GithubAuthenticationCard`, `FolderBrowserModal`
- Updated import usage:
  - `src/components/sidebar/view/subcomponents/SidebarModals.tsx`
    now imports from `../../../project-creation-wizard`.

Implementation details:
- Migrated wizard logic to TypeScript using `type` aliases only.
- Kept component prop types colocated in each component file.
- Split responsibilities by feature:
  - container/orchestration in `ProjectCreationWizard.tsx`
  - API/SSE and request parsing in `data/workspaceApi.ts`
  - GitHub token loading/caching behavior in `useGithubTokens`
  - path/URL helpers in `utils/pathUtils.ts`
- Localized UI-only state to child components:
  - folder browser modal state (current path, hidden folders, create-folder input)
  - path suggestion dropdown state with debounced lookup
- Preserved existing UX flows:
  - step navigation and validation
  - existing/new workspace modes
  - optional GitHub clone + auth modes
  - clone progress via SSE
  - folder browsing + folder creation
- Added focused comments for non-obvious logic (debounce, SSE auth constraint, path edge cases).

src/components/project-creation-wizard/utils/pathUtils.ts

@@ -0,0 +1,52 @@
+import type { WorkspaceType } from '../types';
+
+const SSH_PREFIXES = ['git@', 'ssh://'];
+const WINDOWS_DRIVE_PATTERN = /^[A-Za-z]:\\?$/;
+
+export const isSshGitUrl = (url: string): boolean => {
+  const trimmedUrl = url.trim();
+  return SSH_PREFIXES.some((prefix) => trimmedUrl.startsWith(prefix));
+};
+
+export const shouldShowGithubAuthentication = (
+  workspaceType: WorkspaceType,
+  githubUrl: string,
+): boolean => workspaceType === 'new' && githubUrl.trim().length > 0 && !isSshGitUrl(githubUrl);
+
+export const isCloneWorkflow = (workspaceType: WorkspaceType, githubUrl: string): boolean =>
+  workspaceType === 'new' && githubUrl.trim().length > 0;
+
+export const getSuggestionRootPath = (inputPath: string): string => {
+  const trimmedPath = inputPath.trim();
+  const lastSeparatorIndex = Math.max(trimmedPath.lastIndexOf('/'), trimmedPath.lastIndexOf('\\'));
+  if (lastSeparatorIndex === 2 && /^[A-Za-z]:/.test(trimmedPath)) {
+    return `${trimmedPath.slice(0, 2)}\\`;
+  }
+
+  return lastSeparatorIndex > 0 ? trimmedPath.slice(0, lastSeparatorIndex) : '~';
+};
+
+// Handles root edge cases for Unix-like and Windows paths.
+export const getParentPath = (currentPath: string): string | null => {
+  if (currentPath === '~' || currentPath === '/' || WINDOWS_DRIVE_PATTERN.test(currentPath)) {
+    return null;
+  }
+
+  const lastSeparatorIndex = Math.max(currentPath.lastIndexOf('/'), currentPath.lastIndexOf('\\'));
+  if (lastSeparatorIndex <= 0) {
+    return '/';
+  }
+
+  if (lastSeparatorIndex === 2 && /^[A-Za-z]:/.test(currentPath)) {
+    return `${currentPath.slice(0, 2)}\\`;
+  }
+
+  return currentPath.slice(0, lastSeparatorIndex);
+};
+
+export const joinFolderPath = (basePath: string, folderName: string): string => {
+  const normalizedBasePath = basePath.trim().replace(/[\\/]+$/, '');
+  const separator =
+    normalizedBasePath.includes('\\') && !normalizedBasePath.includes('/') ? '\\' : '/';
+  return `${normalizedBasePath}${separator}${folderName.trim()}`;
+};