[Feature] Support mapping configuration injection for MULTI_DI sync tasks

[yunqiqiliang]

Problem

Currently, creating a multi-table offline sync task (MULTI_DI) via cz-cli task create only generates a task shell without source/target mappings. Users must manually enter the Studio UI to configure:

• Source datasource & database
• Target schema
• Table-to-table mapping rules
• Write mode (e.g., INSERT OVERWRITE)

This breaks the automation workflow and requires manual intervention for every sync task.

Proposed Solution

1. Add --mapping-file <json> parameter to cz-cli task create or cz-cli task config.
2. Support standard JSON format for mapping configuration.
3. Add cz-cli task config <id> --show to view current mapping configuration.

Expected Benefit

• Enable 100% code-based creation of sync tasks.
• Eliminate the "create shell → UI configure" gap.
• Support GitOps and CI/CD pipelines for data integration.

Priority

🟡 P1