feat(node): expose allowExternalBlobOutsideBases in Table.add (#4317)

## Summary

- Add `allowExternalBlobOutsideBases` to the Node `AddDataOptions` and
forward it through N-API to the Rust `AddDataBuilder`.
- Document its default and local-only external blob behavior.
- Cover URI strings and URI objects, option scoping, progress callbacks,
overwrite mode, and remote rejection.

## Validation

- `pnpm test --runInBand` (21 suites passed, 1 skipped; 908 tests
passed, 6 skipped)
- `pnpm lint-ci`
- `pnpm tsc`
- `pnpm run docs`
- `cargo fmt --all -- --check`
- `CC=clang cargo clippy --profile ci -p lancedb-nodejs --all-features
-- -D warnings`

Fixes #4267

nodejs/src/table.rs

@@ -74,13 +74,14 @@ impl Table {
 
     #[napi(
         catch_unwind,
-        ts_args_type = "buf: Buffer, mode: string, progressCallback?: (progress: WriteProgressInfo) => void"
+        ts_args_type = "buf: Buffer, mode: string, progressCallback?: (progress: WriteProgressInfo) => void, allowExternalBlobOutsideBases?: boolean"
     )]
     pub async fn add(
         &self,
         buf: Buffer,
         mode: String,
         progress_callback: Option<ProgressFn>,
+        allow_external_blob_outside_bases: Option<bool>,
     ) -> napi::Result<AddResult> {
         let batches = ipc_file_to_batches(buf.to_vec())
             .map_err(|e| napi::Error::from_reason(format!("Failed to read IPC file: {}", e)))?;
@@ -105,6 +106,9 @@ impl Table {
             return Err(napi::Error::from_reason(format!("Invalid mode: {}", mode)));
         };
 
+        op = op
+            .allow_external_blob_outside_bases(allow_external_blob_outside_bases.unwrap_or(false));
+
         if let Some(tsfn) = progress_callback {
             op = op.progress(move |p| {
                 // NonBlocking: dispatch onto the JS event loop without