feat(observer): add observer mode and disconnect recovery

test/host/test_game_core.c

@@ -312,6 +312,9 @@ static void test_default_map_chunk_bounds(void) {
         size_t written = 0U;
         assert(maze32_game_serialize_view_chunk(&view, chunk, payload, sizeof(payload), &written) ==
                MAZE32_GAME_RESULT_ACCEPTED);
+        if (chunk == 0U) {
+            assert(strstr(payload, "\"connected\":1") != NULL);
+        }
         if (written > largest_chunk) {
             largest_chunk = written;
         }