Phase 4: Template system with auto-select and pre-fill

Backend:
- Add templates.json with 5 template definitions (news, policy, business, fiction, social)
- Add template API (/api/template/list, /api/template/auto-select, /api/template/:id/filter-rules)
- Register template blueprint in Flask app

Frontend:
- Add template API client (frontend/src/api/template.js)
- Add template selector UI in Home.vue (chip buttons + auto-select button)
- Add template state management and auto-select logic

Locale:
- Add template keys for th/en/zh

Entity filter rules in templates.json for context-aware filtering in Step 1.

backend/app/__init__.py

@@ -64,9 +64,11 @@ def create_app(config_class=Config):
     
     # 注册蓝图
     from .api import graph_bp, simulation_bp, report_bp
+    from .api.template import template_bp
     app.register_blueprint(graph_bp, url_prefix='/api/graph')
     app.register_blueprint(simulation_bp, url_prefix='/api/simulation')
     app.register_blueprint(report_bp, url_prefix='/api/report')
+    app.register_blueprint(template_bp, url_prefix='/api/template')
     
     # 健康检查
     @app.route('/health')