feat(observer): add observer mode and disconnect recovery

components/maze32_lobby/include/maze32_protocol.h

@@ -19,6 +19,8 @@ typedef enum {
     MAZE32_MESSAGE_JOIN,
     MAZE32_MESSAGE_RESTORE,
     MAZE32_MESSAGE_START,
+    MAZE32_MESSAGE_MOVE,
+    MAZE32_MESSAGE_DROP_KEY,
     MAZE32_MESSAGE_HEARTBEAT,
     MAZE32_MESSAGE_SUGGEST_NAME,
 } maze32_message_type_t;
@@ -39,6 +41,7 @@ typedef struct {
     maze32_role_t role;
     char name[MAZE32_PLAYER_NAME_MAX_BYTES + 1U];
     char token[MAZE32_SESSION_TOKEN_HEX_LENGTH + 1U];
+    char direction[6U];
 } maze32_client_message_t;
 
 maze32_protocol_result_t maze32_protocol_parse(const char* data, size_t length,

components/maze32_lobby/maze32_protocol.c

@@ -123,6 +123,15 @@ static int payload_field_allowed(maze32_message_type_t type, const char* key, ch
         *fields |= 1U;
         return 1;
     }
+    if (type == MAZE32_MESSAGE_MOVE && strcmp(key, "direction") == 0 && !(*fields & 1U)) {
+        if (strcmp(value, "north") != 0 && strcmp(value, "east") != 0 &&
+            strcmp(value, "south") != 0 && strcmp(value, "west") != 0) {
+            return 0;
+        }
+        memcpy(message->direction, value, strlen(value) + 1U);
+        *fields |= 1U;
+        return 1;
+    }
     return 0;
 }
 
@@ -159,6 +168,9 @@ static int parse_payload(json_cursor_t* cursor, maze32_client_message_t* message
     if (message->type == MAZE32_MESSAGE_RESTORE) {
         return fields == 1U;
     }
+    if (message->type == MAZE32_MESSAGE_MOVE) {
+        return fields == 1U;
+    }
     return fields == 0U;
 }
 
@@ -172,6 +184,12 @@ static maze32_message_type_t message_type(const char* value) {
     if (strcmp(value, "start") == 0) {
         return MAZE32_MESSAGE_START;
     }
+    if (strcmp(value, "move") == 0) {
+        return MAZE32_MESSAGE_MOVE;
+    }
+    if (strcmp(value, "drop_key") == 0) {
+        return MAZE32_MESSAGE_DROP_KEY;
+    }
     if (strcmp(value, "heartbeat") == 0) {
         return MAZE32_MESSAGE_HEARTBEAT;
     }