Time Series Aggregation And Bucketing Helpers

via “time-series data aggregation and downsampling”

** - Provides AI assistants with a secure and structured way to explore and analyze data in [GreptimeDB](https://github.com/GreptimeTeam/greptimedb).

Unique: Abstracts GreptimeDB's native time-bucketing and aggregation functions through semantic MCP operations, allowing LLMs to request 'hourly averages' without understanding SQL window functions or GreptimeDB-specific syntax

vs others: More efficient than post-query aggregation in the LLM layer because it leverages GreptimeDB's optimized time-series aggregation engine, reducing data transfer and computation