feat(frontend): 增强Synthesis Data Detail页面UX体验

[Dallas98]

This pull request introduces several improvements and fixes to both the Helm chart deployment and frontend UI for the Synthesis Task feature. The main changes include correcting Helm template logic, updating service and persistence configuration, and significantly enhancing the Synthesis Data Detail page with better UX for deletion, navigation, and visual clarity.

Helm Chart Improvements

• Fixed the order of nameOverride and chart name references in Helm helper templates to ensure correct naming precedence and compatibility with Helm best practices. (deployment/helm/label-studio/templates/_helpers.tpl) [1] [2] [3]
• Updated default values and service configuration: set fullnameOverride, changed service type to NodePort with a fixed port, and updated the PostgreSQL host and dataset PVC claim name for more predictable deployments. (deployment/helm/label-studio/values.yaml) [1] [2] [3] [4]

Frontend Synthesis Task Improvements

• Improved payload construction in CreateTask.tsx so that the description field is only sent if it contains real content, avoiding unnecessary empty strings. (frontend/src/pages/SynthesisTask/CreateTask.tsx) [1] [2]

Synthesis Data Detail Page UX Enhancements

• Added breadcrumb navigation, chunk/data deletion confirmation overlays, and improved chunk/data list visual styling for a clearer and safer user experience. (frontend/src/pages/SynthesisTask/SynthDataDetail.tsx) [1] [2] [3]
• Refactored chunk and data list rendering: clearer highlighting for active items, chunk/data IDs are always visible, and pagination is only shown when needed. (frontend/src/pages/SynthesisTask/SynthDataDetail.tsx) [1] [2] [3]