10.6CI Integration for LLM Load Tests

# .github/workflows/llm-performance.yml
name: LLM Performance Gate
on:
  push:
    branches: [main]
    paths:
      - 'src/ai/**'       # Only run when AI-related code changes
      - 'prompts/**'

jobs:
  llm-load-test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Run LLM load test
        uses: grafana/k6-action@v0.4.0
        with:
          filename: tests/performance/k6-llm-load-test.js
          flags: --out json=llm-results.json
        env:
          LLM_API_KEY: ${{ secrets.LLM_API_KEY }}

      - name: Check cost threshold
        run: |
          python scripts/check_llm_test_cost.py llm-results.json --max-cost 10.00

      - name: Upload results
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: llm-load-test-results
          path: llm-results.json

LLM load testing requires a mindset shift from "how many requests per second" to "how does cost, latency, and quality behave as concurrency increases." The tools are the same (k6, Locust), but the metrics and constraints are fundamentally different.