feat: support private git repositories with token auth

- Entity: added gitToken and gitBranch columns to Application
- DTO: added gitToken and gitBranch fields to Create/Update DTOs
- Build pipeline: git-clone init container now injects token into
  HTTPS URL for private repo authentication (GitHub PAT, GitLab token, etc.)
- Build pipeline: supports cloning specific branch (default: main)
- Frontend deploy page: added Access Token (password field) and Branch
  inputs when Git Repository source is selected
- Frontend deploy page: Review step shows branch and token status
- Frontend app detail: shows branch badge and 🔑 Private indicator
  when git credentials are configured
- Works with: GitHub, GitLab, Bitbucket, any HTTPS-based git host

frontend/src/types/index.ts

@@ -16,6 +16,8 @@ export interface Application {
   runtime: 'nodejs' | 'laravel';
   databaseType: 'mysql' | 'postgresql' | 'none';
   gitUrl?: string;
+  gitToken?: string;
+  gitBranch?: string;
   codePath?: string;
   envVars?: Record<string, string>;
   cpuRequest: string;
@@ -84,6 +86,8 @@ export interface CreateApplicationDto {
   runtime: 'nodejs' | 'laravel';
   databaseType: 'mysql' | 'postgresql' | 'none';
   gitUrl?: string;
+  gitToken?: string;
+  gitBranch?: string;
   envVars?: Record<string, string>;
   cpuRequest?: string;
   cpuLimit?: string;