fix(tests): handle 404 response for nonexistent library in search filter test

TestCollectionSearchLibraryFilter's 'invalid library_id' case was
expecting a 200 with empty results, but the search handler correctly
returns 404 when no results are found. The test also consumed the
response body for debug logging then tried to JSON-decode the same
body (causing EOF). Add expectedStatus field to the test struct and
return early when a specific non-200 status is expected.

cmd/server/tests/search_test.go

@@ -388,6 +388,7 @@ func TestCollectionSearchLibraryFilter(t *testing.T) {
 		query         string
 		libraryID     string
 		expectedCount int
+		expectedStatus int
 		shouldContain string // Comma-separated list of book IDs to check
 	}{
 		{
@@ -412,10 +413,10 @@ func TestCollectionSearchLibraryFilter(t *testing.T) {
 			shouldContain: book2ID,
 		},
 		{
-			name:          "invalid library_id",
-			query:         "Harry",
-			libraryID:     "00000000-0000-0000-0000-000000000000",
-			expectedCount: 0,
+			name:           "invalid library_id",
+			query:          "Harry",
+			libraryID:      "00000000-0000-0000-0000-000000000000",
+			expectedStatus: http.StatusNotFound,
 		},
 	}
 
@@ -435,10 +436,9 @@ func TestCollectionSearchLibraryFilter(t *testing.T) {
 				_ = Body.Close()
 			}(resp.Body)
 
-			// Log response for debugging
-			if resp.StatusCode != http.StatusOK {
-				bodyBytes, _ := io.ReadAll(resp.Body)
-				t.Logf("ERROR %d: %s", resp.StatusCode, string(bodyBytes))
+			if tt.expectedStatus != 0 {
+				require.Equal(t, tt.expectedStatus, resp.StatusCode)
+				return
 			}
 
 			var result []map[string]interface{}