fix: improve minimap behavior for multi-span highlights

[cuspymd]

Summary

• emphasize all spans in a highlight group when clicking a minimap marker
• build minimap tooltip text from the full multi-span highlight group instead of only the representative span
• keep existing minimap scrolling behavior while improving multi-span highlight feedback

Testing

• npm test -- --runInBand
• npx playwright test

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Escape groupId before querySelectorAll selector interpolation

groupId is inserted raw into an attribute selector here, so a valid imported ID containing selector metacharacters (for example ' or ]) will cause querySelectorAll(...) to throw a SyntaxError and abort updateMarkers(), which leaves the minimap broken for that page. This is reachable because highlight import currently accepts any non-empty string for groupId; use CSS.escape(groupId) (or a non-selector lookup) before building the selector (and apply the same fix to the identical pattern in highlightTemporarily).

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