Copy crossing island tag to crossing nodes

[KTibow]

Description, Motivation & Context

When iD detects a road/path crossing and suggests creating a missing crossing node, it already copies known crossing details from the crossing way to the generated highway=crossing node. This currently includes the crossing type and crossing:markings.

This extends that behavior to also copy crossing:island from the crossing way to the generated crossing node.

This keeps refuge island information with the crossing node when iD automatically creates or repairs the crossing point, matching the existing behavior for crossing markings.

Testing

• npm run lint -- --quiet passed.
• npm run test:once -- test/spec/validations/crossing_ways.js passed its assertions: 83 passed, including the new crossing:island test.
• That focused spec still emitted the same unhandled SyntaxError: "undefined" is not valid JSON errors from history.migrateHistoryData during coreContext setup on my laptop. This matches the baseline local test issue seen in unrelated existing specs.
• Verified in preview environment: correctly copies crossing island tag over

Disclosure

Generated with GPT-5.5 with human oversight.

[Dimitar5555]

The linear way might cover more than one carriageway, so it would have crossing:island=yes across the whole length. But each hw=crossing node would not have such island, so crossing:island=yes on the node would be incorrect. See the example situation below.

[KTibow]

That's true but I'd expect it to be rather uncommon and easily manually fixable (remember the add point action is manually triggered). I'd also argue that that specific crossing would be better mapped as a crossing + a foot path + another crossing, especially when the current way's crossing:island=yes is mostly wasted (algorithms care about crossing nodes, not crossing ways).