feat: Android login/register add mandatory agreement checkbox

- LoginScreen: add agreement checkbox, disabled until checked
- RegisterScreen: add agreement checkbox, disabled until checked
- RegisterViewModel: pass agreed_terms/agreed_terms_version to API
- RegisterRequest DTO: add agreedTerms/agreedTermsVersion fields
- Also include 3 template scripts missed in previous commit

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/scripts/templates/template_dev_codegen.py

@@ -14,8 +14,8 @@ import time
 import requests
 
 BASE = os.getenv("PLATFORM_BASE_URL", "http://127.0.0.1:8037").rstrip("/")
-USER = os.getenv("PLATFORM_USERNAME", "admin")
-PWD = os.getenv("PLATFORM_PASSWORD", "123456")
+USER = os.getenv("PLATFORM_USERNAME")
+PWD = os.getenv("PLATFORM_PASSWORD")
 TEMPLATE_ID = "template_dev_codegen"
 DEFAULT_NAME = os.getenv("TARGET_NAME") or f"场景模板_研发_{int(time.time())}"