feat(website): restructure the benchmark page into clearer sections

[zantvoort]

Summary

Restructures /benchmarks for readability. No benchmark data, numbers, rankings, error margins, versions or benchmark source are changed — every value renders from the same WORKLOADS constant as before.

Sections

The page is reorganised under four clear headings: Performance results, Code comparison, Inspect each workload, and Methodology and reproduction. No content was removed.

Copy

• New opening copy; a workload-coverage line at the top of the results.
• First stat card now reads "fastest framework above JDBC" (and card 2 "fastest framework", for consistency and because not every compared library is a traditional ORM).
• Network-overhead sentence reworded so it no longer implies a directly measured mapping overhead.
• The LOC comparison keeps its numbers but is qualified as an illustration of these implementations, not a universal complexity measure.
• A neutral Scope and limitations box (single-threaded latency on PostgreSQL; not throughput, pooling, startup, memory, native-image or other databases).
• A closing call to action (Get started → /quickstart, View benchmark source → the benchmark repo).

Inspect each workload

Each workload shows Storm's implementation by default; the other six libraries are one <select> away and the SQL one "Show SQL" toggle away, both in the editor's own title bar (no extra panels or toggle links). The Show SQL toggle is keyboard-operable (role="button", tabindex, aria-expanded, Enter/Space) — the only accessibility gap in the editor chrome.

Verification

npm run build succeeds. Broken-link warnings in the build are pre-existing /docs/* versioned-docs anchors, unrelated to this change.