feat: Enable historical benchmark tracking with GitHub Pages

- Created gh-pages branch for storing benchmark history
- Re-enabled benchmark-action with auto-push to gh-pages
- Benchmark results will be stored and visualized at:
  https://spandigital.github.io/cel2sql/dev/bench/

Features:
- Historical trend tracking across commits
- Automatic PR comments on performance changes >150%
- Visual charts showing performance over time
- Permanent storage of benchmark results

Updated documentation to reflect new capabilities.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: richardwooding

.github/workflows/ci.yml

@@ -65,4 +65,16 @@ jobs:
       run: go mod download
 
     - name: Run benchmarks
-      run: go test -bench=. -benchmem -benchtime=1s -run=^$$ ./...
+      run: go test -bench=. -benchmem -benchtime=1s -run=^$$ ./... | tee benchmark-results.txt
+
+    - name: Store benchmark result
+      uses: benchmark-action/github-action-benchmark@v1
+      with:
+        tool: 'go'
+        output-file-path: benchmark-results.txt
+        github-token: ${{ secrets.GITHUB_TOKEN }}
+        auto-push: true
+        comment-on-alert: true
+        alert-threshold: '150%'
+        fail-on-alert: false
+        summary-always: true

CLAUDE.md

@@ -266,9 +266,10 @@ BenchmarkConvertOperators/logical_and-12   943438    1255 ns/op    2154 B/op
 
 Benchmarks run automatically on every PR and push to main:
 - Runs on Go 1.24.x
-- Validates that all benchmarks complete successfully
-- Detects performance regressions
-- Ensures code changes don't break benchmark tests
+- Stores benchmark results in gh-pages branch for historical tracking
+- Comments on PRs when performance changes >150%
+- Generates visual charts at https://spandigital.github.io/cel2sql/dev/bench/
+- Provides summary of all benchmark results
 
 #### Comparing Benchmark Results