feat(link-wizard): save soundcloud followers

src/api/artistSearch/mergeCandidateSelection.test.ts

@@ -136,6 +136,36 @@ describe("mergeCandidateSelection", () => {
 
     expect(update.providerUrl).toEqual({ spotify: candidate.url });
   });
+
+  it("carries soundcloud followers when a soundcloud url is selected", () => {
+    const candidate = makeCandidate({
+      url: "https://soundcloud.com/artist",
+      followers: 4200,
+    });
+
+    const update = mergeCandidateSelection(candidate, "soundcloud", ["url"]);
+
+    expect(update.soundcloudFollowers).toBe(4200);
+  });
+
+  it("writes nothing for soundcloud candidates with null followers", () => {
+    const candidate = makeCandidate({
+      url: "https://soundcloud.com/artist",
+      followers: null,
+    });
+
+    const update = mergeCandidateSelection(candidate, "soundcloud", ["url"]);
+
+    expect(update).not.toHaveProperty("soundcloudFollowers");
+  });
+
+  it("does not carry followers for spotify candidates", () => {
+    const candidate = makeCandidate({ followers: 1000 });
+
+    const update = mergeCandidateSelection(candidate, "spotify", ["url"]);
+
+    expect(update).not.toHaveProperty("soundcloudFollowers");
+  });
 });
 
 function makeCandidate(overrides: Partial<Candidate> = {}): Candidate {

src/api/artistSearch/mergeCandidateSelection.ts

@@ -4,6 +4,7 @@ export interface CandidateUpdate {
   providerUrl?: Partial<Record<Provider, string>>;
   image_url?: string | null;
   description?: string | null;
+  soundcloudFollowers?: number;
 }
 
 export type SelectableField = "url" | "image" | "description";
@@ -23,6 +24,12 @@ export function mergeCandidateSelection(
 
   if (fields.includes("url")) {
     updates.providerUrl = { [provider]: candidate.url };
+
+    // Spotify stopped returning followers for non-extended apps, so only
+    // SoundCloud has a real value to persist.
+    if (provider === "soundcloud" && candidate.followers !== null) {
+      updates.soundcloudFollowers = candidate.followers;
+    }
   }
 
   if (fields.includes("image") && candidate.imageUrl && !staged.image_url) {

src/api/artists/useUpdateArtist.ts

@@ -21,7 +21,7 @@ export type UpdateArtistUpdates = Partial<
     | "time_end"
     | "archived"
   >
-> & { genre_ids?: string[] };
+> & { genre_ids?: string[]; soundcloud_followers?: number };
 
 // Mutation function
 async function updateArtist(variables: {
@@ -76,6 +76,24 @@ async function updateArtist(variables: {
     }
   }
 
+  if (updates.soundcloud_followers !== undefined) {
+    // Only the count is seeded, so last_sync stays null to keep the row
+    // eligible for the next sync-artist-data run, which may overwrite it.
+    const { error } = await supabase.from("soundcloud").upsert(
+      {
+        artist_id: id,
+        followers_count: updates.soundcloud_followers,
+        last_sync: null,
+      },
+      { onConflict: "artist_id" },
+    );
+
+    if (error) {
+      console.error("Error saving soundcloud followers:", error);
+      throw new Error("Failed to save SoundCloud followers");
+    }
+  }
+
   if (genre_ids !== undefined) {
     const { data: currentGenres, error: currentGenresError } = await supabase
       .from("artist_music_genres")

src/pages/admin/festivals/LinkWizard/LinkWizardStep.tsx

@@ -58,6 +58,7 @@ const linkStepSchema = z.object({
     }),
   image_url: z.string().nullable().optional(),
   description: z.string().nullable().optional(),
+  soundcloud_followers: z.number().optional(),
 });
 
 export type LinkStepData = z.infer<typeof linkStepSchema>;
@@ -214,6 +215,13 @@ export function LinkWizardStep({
         shouldDirty: true,
       });
     }
+    // Reassigned (even to undefined) on every SoundCloud URL pick so a
+    // previous candidate's count never pairs with a new URL.
+    if (update.providerUrl?.soundcloud !== undefined) {
+      form.setValue("soundcloud_followers", update.soundcloudFollowers, {
+        shouldDirty: true,
+      });
+    }
   }
 
   // The picked types must persist before the step advances — the artist save
@@ -247,6 +255,10 @@ export function LinkWizardStep({
       updates.description = data.description;
     }
 
+    if (data.soundcloud_followers !== undefined) {
+      updates.soundcloud_followers = data.soundcloud_followers;
+    }
+
     updateArtistMutation.mutate(
       { id: artist.id, updates },
       {

supabase/migrations/20261013060000_soundcloud_admin_write_policies.sql

@@ -0,0 +1,11 @@
+-- Link Wizard persists the follower count of a selected SoundCloud candidate
+-- from the admin client; previously only the sync function (service role)
+-- could write this table.
+CREATE POLICY "Admins can insert soundcloud data" ON public.soundcloud
+    FOR INSERT TO authenticated
+    WITH CHECK (public.can_edit_artists(auth.uid()));
+
+CREATE POLICY "Admins can update soundcloud data" ON public.soundcloud
+    FOR UPDATE TO authenticated
+    USING (public.can_edit_artists(auth.uid()))
+    WITH CHECK (public.can_edit_artists(auth.uid()));