fix: 7d/30d tabs disabled when metric panel is active — lazy-fetch panel long-range series

[Flotapponnier]

Problem

On every bench with metric panels (columns like "Volume routed" on `hyperliquid-frontends`), clicking a panel disables the 7d and 30d time-range pills — hover shows "Switch off the metric panel to see long-range history" even though the underlying Prom data exists.

Root cause

1. Worker computes panel-level `seriesByProvider7d/30d` correctly (materialize/load.ts:980-997)
2. `slimBenchmarkForCache()` strips those from the cached bench payload to stay under `unstable_cache`'s 2 MB limit
3. Chart's lazy-fetch of `/api/series/[slug]?range=7d|30d` returns ONLY bench-level series, no panel scope
4. Chart guard `has30d = !panelActive || !!seriesOverride30d` evaluates false → tab disabled

Fix

A) `/api/series/[slug]?panel=` — new optional param that returns panel-specific series from the same blob/materialized snapshot (already contains them). Cache key bumped to v5.

B) `time-series-chart/index.tsx` — new prop `activePanelId`, dedicated `useEffect` fetches panel 7d/30d when active. Result cached per panel id so switching between panels is instant. `has7d`/`has30d` and `pickPanel()` extended to use lazy panel maps.

C) `benchmark-body.tsx` — passes `activePanelId={activePanel?.id ?? null}` to the chart.

No cache-size impact (long-range series still stripped). CDN cache handles panel fan-out same as bench-level (60s s-maxage + 300s SWR).

Test plan

• /benchmarks/hyperliquid-frontends → click "Volume routed" panel → 7d + 30d pills enabled and load real data
• Same on other panel-bearing benches (perp-fees, pm-*, etc.)
• Deactivate panel → tabs still work with bench-level data
• Switch back and forth between two panels → both cached, no re-fetch