Add benchmark documentation and CI verification

Created comprehensive benchmark documentation page organized by component
(ledger). Added bash scripts for building and running benchmarks, which
are verified in CI to ensure commands exist in Makefile.

Documentation includes:
- Overview of criterion-based benchmarking
- Build and run instructions using bash scripts
- Ledger database benchmark details (account generation and merkle root
  computation)

CI verification added to test-docs-scripts workflow:
- Verifies benchmark scripts are executable
- Confirms make targets exist in Makefile
- Does not run benchmarks to avoid long CI times

Author: dannywillems

.github/workflows/test-docs-scripts.yaml

@@ -221,6 +221,29 @@ jobs:
           # We'll just check if it was installed via Homebrew
           docker --version || echo "Docker installed but not running (expected on macOS CI)"
 
+  test-benchmark-commands:
+    name: Verify Benchmark Commands
+    runs-on: ubuntu-latest
+    if: github.event_name == 'schedule' || github.event_name == 'workflow_dispatch' || contains(github.event.pull_request.labels.*.name, 'test-doc-scripts')
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v5
+
+      - name: Verify benchmark scripts and commands
+        run: |
+          # Check if scripts exist and are executable
+          test -x ./website/docs/developers/scripts/benchmarks/build-benchmarks.sh
+          test -x ./website/docs/developers/scripts/benchmarks/run-all-benchmarks.sh
+          test -x ./website/docs/developers/scripts/benchmarks/run-database-benchmark.sh
+
+          # Verify the make targets referenced in scripts exist in Makefile
+          grep -q "^build-benches:" Makefile
+          grep -q "^bench:" Makefile
+          grep -q "^bench-database:" Makefile
+
+          echo "SUCCESS: All benchmark commands verified"
+
   test-update-ocaml-node-script:
     name: Test Update OCaml Node Script
     runs-on: ${{ matrix.os }}