next.js

0a074bda - fix(dev-overlay): Tidy up issues/insight menu and tab overlay (#94549)

fix(dev-overlay): Tidy up issues/insight menu and tab overlay (#94549) ### What? Tidies up how the dev overlay surfaces Issues vs Insights: - Tab bar: when there are no insights, the Insights tab is hidden. When there are no issues but there are insights, the Issues tab stays in place but reads `No issues` (disabled, no hover). - Menu row: shows one row labeled `Issues`, `Insights`, or `Issues · Insights` with a red badge for issues and an amber badge for insights, matching the trigger pill colors. ### Verification Test-app scenarios on the [error-messages-overhaul demo](https://error-messages-overhaul-ibsl.labs.vercel.dev/): [41-subnav-cookies](https://error-messages-overhaul-ibsl.labs.vercel.dev/scenario/41-subnav-cookies), [42-subnav-fetch](https://error-messages-overhaul-ibsl.labs.vercel.dev/scenario/42-subnav-fetch). ### Why? Reported by icyJoseph in Slack. The red `Issues 1` chip on an insights-only state looked like a real error; the `0/0` placeholder was inconsistent. <!-- NEXT_JS_LLM_PR -->