DuckDB.of doesn't ingest relative FileAttachments

[Fil]

EDIT: this now works, but needs to be cleaned up once we ship a new version of stdlib.

---

This does not currently work:

const db = await DuckDBClient.of({penguins: FileAttachment("simple-parquet.parquet")});

A work-around is to force the URL to be absolute:

function absoluteFA(FA) {
  const {url} = FA;
  FA.url = async function() {
    return new URL(await url.apply(FA), document.location.href).href;
  }
  return FA;
}

then call:

const db = await DuckDBClient.of({penguins: absoluteFA(FileAttachment("simple-parquet.parquet"))});

Maybe that could be fixed in stdlib, https://github.com/observablehq/stdlib/blob/301bd60f43b7416ea4a82a297f0dd287bef83410/src/duckdb.js#L174C36-L174C45

[Fil]

Another workaround:

const db = DuckDBClient.of({
  penguins: {
    file: {
      name: "penguins.parquet",
      url: () => "blob:",
      arrayBuffer: () => FileAttachment("penguins.parquet").arrayBuffer()
    }
  }
})

[Fil]

This PR works for me observablehq/stdlib#389

[Fil]

When we fix stdlib, revert the (neat) work-around added in 262d2ef

[Fil]

depends on observablehq/runtime#367