[Feature] Add Dynamic Table status query and refresh control commands

[yunqiqiliang]

Problem

Dynamic Table refresh behavior is opaque via CLI. Users cannot easily check:

• Next scheduled refresh time
• Current refresh status (IDLE, RUNNING, FAILED)
• Last refresh duration and mode (FULL/INCREMENTAL)
• Why a table didn't refresh at expected time (e.g., scheduleStartTime confusion)

Currently, users must run complex SHOW DYNAMIC TABLE REFRESH HISTORY queries and parse output manually.

Proposed Solution

1. Add cz-cli dt status <table> command:
   • Returns: interval, next_trigger_time, last_refresh_state, last_refresh_mode, error_message
2. Add cz-cli dt refresh <table> [--mode full|incremental] command:
   • Wraps REFRESH DYNAMIC TABLE SQL with validation and progress tracking.
3. Clarify documentation: REFRESH INTERVAL calculates from creation/last refresh time, not wall-clock alignment.

Expected Benefit

• Make Dynamic Table scheduling observable and intervenable.
• Reduce troubleshooting time for "why didn't it refresh?" scenarios.
• Provide intuitive CLI interface for common DT operations.

Priority

🔴 P0