Update docs/guides to change how WebSocketData gets passed

[alii]

…nce routes/static breaks the existing api)

What does this PR do?

• Documentation or TypeScript types (it's okay to leave the rest blank in this case)
• Code changes

[robobun]

^{Updated 11:31 PM PT - May 21st, 2025}

❌ @alii, your commit 167a7b2 has 1 failures in Build #17102:

• test/js/bun/spawn/spawn.test.ts - 1 failing on 🪟 2019 x64
• test/js/bun/spawn/spawn.test.ts - 1 failing on 🪟 2019 x64-baseline

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🧪   To try this PR locally:

bunx bun-pr 19780

That installs a local version of the PR into your bun-19780 executable, so you can run:

bun-19780 --bun

[RiskyMH]

fixes second part of #19246 :)

[chevcast]

Gross. I really hope this doesn't become the official way to type socket context data.

[alii]

@chevcast I agree it's not great. This was a symptom of the fact that adding routes: {} broke the WebSocket data. Unfortunately it's non-trivial to fix without partial type parameter inference

The reason this PR hasn't merged yet is because it might be even more confusing to have an "official" temporary workaround until either we are able to decide on a suitable breaking change for Bun.serve, or TypeScript implements partial type parameter inference.

[alii]

Closing as fixing in #20918