feat(frontend): update generated API types and Geschichte routes for JourneyItem model

- api.ts: add GeschichteType, JourneyItem, GeschichteSummary schemas;
  remove documentId param from list endpoint; change list response to
  GeschichteSummary[]; add type + items to Geschichte; remove documents field
- GeschichteEditor: remove DocumentMultiSelect + documentIds from payload
  (journey items are managed via the future Lesereisen editor, not here)
- GET /geschichten page: remove documentId filter from server load + URL logic
- geschichten/new: remove documentId pre-population from server load
- geschichten/[id]: replace g.documents with g.items (document-backed JourneyItems)
- geschichten/new + [id]/edit: remove documentIds from submit payload type

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/lib/generated/api.ts

@@ -2016,7 +2016,6 @@ export interface components {
             /** @enum {string} */
             status?: "DRAFT" | "PUBLISHED";
             personIds?: string[];
-            documentIds?: string[];
         };
         Geschichte: {
             /** Format: uuid */
@@ -2025,9 +2024,11 @@ export interface components {
             body?: string;
             /** @enum {string} */
             status: "DRAFT" | "PUBLISHED";
+            /** @enum {string} */
+            type: "STORY" | "JOURNEY";
             author?: components["schemas"]["AppUser"];
             persons?: components["schemas"]["Person"][];
-            documents?: components["schemas"]["Document"][];
+            items?: components["schemas"]["JourneyItem"][];
             /** Format: date-time */
             createdAt: string;
             /** Format: date-time */
@@ -2035,6 +2036,32 @@ export interface components {
             /** Format: date-time */
             publishedAt?: string;
         };
+        JourneyItem: {
+            /** Format: uuid */
+            id: string;
+            /** Format: int32 */
+            position: number;
+            /** Format: uuid */
+            documentId?: string;
+            note?: string;
+        };
+        GeschichteSummary: {
+            /** Format: uuid */
+            id: string;
+            title: string;
+            /** @enum {string} */
+            status: "DRAFT" | "PUBLISHED";
+            /** @enum {string} */
+            type: "STORY" | "JOURNEY";
+            author?: {
+                firstName?: string;
+                lastName?: string;
+                email: string;
+            };
+            body?: string;
+            /** Format: date-time */
+            publishedAt?: string;
+        };
         CreateTranscriptionBlockDTO: {
             /** Format: int32 */
             pageNumber?: number;
@@ -3576,7 +3603,6 @@ export interface operations {
             query?: {
                 status?: "DRAFT" | "PUBLISHED";
                 personId?: string[];
-                documentId?: string;
                 limit?: number;
             };
             header?: never;
@@ -3591,7 +3617,7 @@ export interface operations {
                     [name: string]: unknown;
                 };
                 content: {
-                    "*/*": components["schemas"]["Geschichte"][];
+                    "*/*": components["schemas"]["GeschichteSummary"][];
                 };
             };
         };