Fix duplicate upload notifications for collection track publishes (#14031)

## Summary
- Ensure collection (playlist/album) child tracks are explicitly marked
as playlist uploads before publish.
- Preserve `is_playlist_upload` through web upload metadata adaptation
and SDK upload schema parsing.
- Prevent backend `create` track notifications from fanning out for each
child track in collection upload retries.

## Changes
- `packages/common/src/api/tan-query/upload/usePublishCollection.ts`:
set `metadata.is_playlist_upload = true` when composing child track
metadata for collection uploads.
- `packages/common/src/adapters/track.ts`: include `is_playlist_upload`
in `trackMetadataForUploadToSdk()` output.
- `packages/sdk/src/sdk/api/tracks/types.ts`: add `isPlaylistUpload` to
`UploadTrackMetadataSchema` so strict parsing keeps the field.

## Notes
- Root cause traced to missing propagation of `is_playlist_upload`;
discovery-provider trigger logic only suppresses per-track create
notifications when this field is true.
- Targeted tests were not runnable in this environment because `vitest`
is not available in the package runtime path.

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Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: Ray Jacobson <raymondjacobson@users.noreply.github.com>

Author: 3 people

packages/common/src/adapters/track.ts

@@ -280,6 +280,7 @@ export const trackMetadataForUploadToSdk = (
         'is_download_gated',
         'is_downloadable',
         'is_original_available',
+        'is_playlist_upload',
         'is_scheduled_release',
         'bpm',
         'is_custom_bpm',

packages/common/src/api/tan-query/upload/usePublishCollection.ts

@@ -239,6 +239,8 @@ function combineMetadata(
   // Set download & hidden status
   metadata.is_downloadable = !!collectionMetadata.is_downloadable
 
+  // Marks child tracks so backend suppresses per-track follower create notifications.
+  metadata.is_playlist_upload = true
   metadata.is_unlisted = !!collectionMetadata.is_private
   if (collectionMetadata.is_private && collectionMetadata.field_visibility) {
     // Convert any undefined values to booleans

packages/sdk/src/sdk/api/tracks/types.ts

@@ -194,6 +194,7 @@ export const UploadTrackMetadataSchema = z.object({
   coverArtSizes: z.optional(z.string()),
   isDownloadable: z.optional(z.boolean()),
   isOriginalAvailable: z.optional(z.boolean()),
+  isPlaylistUpload: z.optional(z.boolean()),
   ddexReleaseIds: z.optional(z.record(z.string()).nullable()),
   ddexApp: z.optional(z.string()).nullable(),
   artists: z.optional(z.array(DDEXResourceContributor)).nullable(),