refactor: update Bruno API collection for media-items system

- Remove all ebook-specific API requests (15 files deleted)
- Rename Scan Ebooks.bru to Scan Media Items.bru
- Update API paths from /api/ebooks to /api/media-items
- Update base URL and environment configuration
- Maintain all existing media-items, library, auth, and progress tests

Aligns Bruno collection with unified media-items API architecture

bruno/library/Get Library Folders.bru

@@ -6,6 +6,7 @@ meta {
 
 get {
   url: {{base_url}}/api/libraries/{{library_id}}/folders
+  body: none
   auth: inherit
 }
 
@@ -13,52 +14,6 @@ headers {
   Content-Type: application/json
 }
 
-tests {
-  test_get_library_folders_success(status, headers, body) {
-    if (status !== 200) {
-      throw new Error("Expected status 200, got " + status);
-    }
-
-    const contentType = headers["content-type"];
-    if (!contentType || !contentType.includes("application/json")) {
-      throw new Error("Expected content-type to contain application/json, got " + contentType);
-    }
-
-    // Verify response body is valid JSON and has expected structure
-    let data;
-    try {
-      data = JSON.parse(body);
-    } catch (e) {
-      throw new Error("Response body is not valid JSON");
-    }
-
-    if (!Array.isArray(data)) {
-      throw new Error("Expected response body to be an array");
-    }
-
-    // Validate each folder in array
-    data.forEach((folder, index) => {
-      if (!folder || typeof folder !== "object") {
-        throw new Error("Folder at index " + index + " is not an object");
-      }
-      
-      if (!folder.id) {
-        throw new Error("Folder at index " + index + " missing required field: id");
-      }
-      
-      if (!folder.folder_path) {
-        throw new Error("Folder at index " + index + " missing required field: folder_path");
-      }
-      
-      if (!folder.library_id) {
-        throw new Error("Folder at index " + index + " missing required field: library_id");
-      }
-    });
-
-    return true;
-  }
-}
-
 vars:pre-request {
   libraryId: "8821b703-h29b-71d4-d716-446655440003"
 }
@@ -97,4 +52,4 @@ docs {
   - 403: Forbidden (library access denied)
   - 404: Library not found
   - 500: Internal server error
-}
+}