Add streaming insert API option for production

[irjudson]

Add opt-in streaming insert API for production deployments alongside current load job API.

Priority: Medium
Component: BigQuery Integration

Current: Load job API (free tier compatible)
Add: Streaming insert option with:

• Lower latency for real-time use cases
• Different cost model (may be preferred at scale)
• Configurable per table

Reference: docs/plans/2025-11-12-multi-table-tdd-design.md

[irjudson]

Completed in PR #14.

The plugin now supports both insertion APIs:

• Load Job API (default) - free, higher latency
• Streaming Insert API (opt-in via useStreamingAPIs: true) - low latency, has costs

Configuration example:

bigquery:
  tables:
    - id: vessel_positions
      useStreamingAPIs: false  # Default batch/free
    - id: port_events  
      useStreamingAPIs: true   # Real-time