feat: taste onboarding for new listeners (M6)

- GET /onboarding offers the library's top artists (with album covers)
  and genres and says whether to show it (not done and < 10 plays);
  PUT /me/onboarding stores the choice or a skip (migration 00009).
- The recommender seeds the taste from it while the user has fewer than
  30 scored tracks: chosen artists' tracks +1, chosen genres +0.5.
- Web: onboarding replaces the wave on the home page until done or
  skipped; artist grid with covers, genre chips, at least 3 artists.
- e2e journey and the recommender DB test cover it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/api-client/src/generated/schema.ts

@@ -1066,6 +1066,43 @@ export interface paths {
         patch?: never;
         trace?: never;
     };
+    "/api/v1/onboarding": {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        /**
+         * Онбординг вкуса — исполнители и жанры библиотеки для выбора
+         * @description `required` — показать онбординг: пользователь его не проходил и не пропускал, а своей истории почти нет.
+         */
+        get: operations["getOnboarding"];
+        put?: never;
+        post?: never;
+        delete?: never;
+        options?: never;
+        head?: never;
+        patch?: never;
+        trace?: never;
+    };
+    "/api/v1/me/onboarding": {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        get?: never;
+        /** Сохранить выбор онбординга (или пропуск — пустые списки) */
+        put: operations["saveOnboarding"];
+        post?: never;
+        delete?: never;
+        options?: never;
+        head?: never;
+        patch?: never;
+        trace?: never;
+    };
     "/api/v1/wave/options": {
         parameters: {
             query?: never;
@@ -1181,6 +1218,26 @@ export interface paths {
 export type webhooks = Record<string, never>;
 export interface components {
     schemas: {
+        Onboarding: {
+            required: boolean;
+            artists: {
+                /** Format: uuid */
+                id: string;
+                name: string;
+                track_count: number;
+                /** @description Обложка самого большого альбома исполнителя */
+                cover_url: string | null;
+                cover_colors: string[];
+            }[];
+            genres: {
+                name: string;
+                track_count: number;
+            }[];
+        };
+        OnboardingChoice: {
+            artist_ids: string[];
+            genres: string[];
+        };
         UserRef: {
             /** Format: uuid */
             id: string;
@@ -3599,6 +3656,50 @@ export interface operations {
             default: components["responses"]["Problem"];
         };
     };
+    getOnboarding: {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        requestBody?: never;
+        responses: {
+            /** @description Варианты и состояние */
+            200: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "application/json": components["schemas"]["Onboarding"];
+                };
+            };
+            default: components["responses"]["Problem"];
+        };
+    };
+    saveOnboarding: {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        requestBody: {
+            content: {
+                "application/json": components["schemas"]["OnboardingChoice"];
+            };
+        };
+        responses: {
+            /** @description Сохранено */
+            204: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content?: never;
+            };
+            default: components["responses"]["Problem"];
+        };
+    };
     getWaveOptions: {
         parameters: {
             query?: never;