feat: integrate AbstractWizard for initialization

- Add wizard service (git.hangman-lab.top/hzhang/abstract-wizard:latest)
- Add wizard-init service: uploads init-config on first deploy
- Backend reads wizard config on startup, creates admin user + default project
- Add init-config/harborforge.json with default admin credentials
- Update README with initialization docs
- Startup order: mysql → wizard → wizard-init → backend → frontend

init-config/harborforge.json

@@ -0,0 +1,12 @@
+{
+  "admin": {
+    "username": "admin",
+    "email": "admin@harborforge.local",
+    "password": "changeme",
+    "full_name": "HarborForge Admin"
+  },
+  "default_project": {
+    "name": "Default",
+    "description": "默认项目"
+  }
+}