feat(streaming): introduce WebSocket Streaming API bridging event bus

ApiServer: add AsyncWebSocket at /ws; accept JSON {event, payload} (string or object) and dispatch via ctx.fire; mirror all local events to clients using NodeContext::onAny.\nNodeContext: add onAny subscriber API.\nNeoPatternService: add api/neopattern/color event to set solid color.\nCluster: centralize cluster/broadcast sending in core; services delegate.\nAPI: add generic /api/node/event and /api/cluster/event endpoints in respective services.\nTests: add ws-color-client, ws-cluster-broadcast-color, http-cluster-broadcast-color.\nDocs: add StreamingAPI.md; update README and test/README.\nFixes: robust WS JSON parsing on ESP8266 and payload handling.

src/spore/core/ApiServer.cpp

@@ -87,6 +87,10 @@ void ApiServer::serveStatic(const String& uri, fs::FS& fs, const String& path, c
 }
 
 void ApiServer::begin() {
+    // Setup streaming API (WebSocket)
+    setupWebSocket();
+    server.addHandler(&ws);
+    
     // Register all service endpoints
     for (auto& service : services) {
         service.get().registerEndpoints(*this);
@@ -95,3 +99,59 @@ void ApiServer::begin() {
     
     server.begin();
 }
+
+void ApiServer::setupWebSocket() {
+    ws.onEvent([this](AsyncWebSocket* server, AsyncWebSocketClient* client, AwsEventType type, void* arg, uint8_t* data, size_t len) {
+        if (type == WS_EVT_DATA) {
+            AwsFrameInfo* info = (AwsFrameInfo*)arg;
+            if (info->final && info->index == 0 && info->len == len && info->opcode == WS_TEXT) {
+                // Parse directly from the raw buffer with explicit length
+                JsonDocument doc;
+                DeserializationError err = deserializeJson(doc, (const char*)data, len);
+                if (!err) {
+                    LOG_INFO("API", "Received event: " + String(doc["event"].as<String>()));
+                    String raw; raw.reserve(len + 1); for (size_t i = 0; i < len; ++i) raw += (char)data[i];
+                    LOG_INFO("API", "Received raw WS data: " + raw);
+                    String eventName = doc["event"].as<String>();
+                    String payloadStr;
+                    if (doc["payload"].is<const char*>()) {
+                        payloadStr = doc["payload"].as<const char*>();
+                    } else if (!doc["payload"].isNull()) {
+                        // If payload is an object/array, serialize it
+                        String tmp; serializeJson(doc["payload"], tmp); payloadStr = tmp;
+                    }
+                    // Allow empty payload; services may treat it as defaults
+                    if (eventName.length() > 0) {
+                        std::string ev = eventName.c_str();
+                        ctx.fire(ev, &payloadStr);
+                        // Acknowledge
+                        client->text("{\"ok\":true}");
+                    } else {
+                        client->text("{\"error\":\"Missing 'event'\"}");
+                    }
+                } else {
+                    client->text("{\"error\":\"Invalid JSON\"}");
+                }
+            }
+        } else if (type == WS_EVT_CONNECT) {
+            client->text("{\"hello\":\"ws connected\"}");
+        } else if (type == WS_EVT_DISCONNECT) {
+            // No-op
+        }
+    });
+
+    // Subscribe to all local events and forward to websocket clients
+    ctx.onAny([this](const std::string& event, void* dataPtr) {
+        String* payloadStr = static_cast<String*>(dataPtr);
+        JsonDocument doc;
+        doc["event"] = event.c_str();
+        if (payloadStr) {
+            doc["payload"] = *payloadStr;
+        } else {
+            doc["payload"] = "";
+        }
+        String out;
+        serializeJson(doc, out);
+        ws.textAll(out);
+    });
+}

src/spore/core/NodeContext.cpp

@@ -29,4 +29,11 @@ void NodeContext::fire(const std::string& event, void* data) {
     for (auto& cb : eventRegistry[event]) {
         cb(data);
     }
+    for (auto& acb : anyEventSubscribers) {
+        acb(event, data);
+    }
+}
+
+void NodeContext::onAny(AnyEventCallback cb) {
+    anyEventSubscribers.push_back(cb);
 }