refactor: reorganize project structure with modern C++ namespace organization

- Restructure include/ and src/ directories with logical grouping
- Move core components to spore/core/ (NodeContext, NetworkManager, TaskManager, ClusterManager, ApiServer)
- Move services to spore/services/ (NodeService, NetworkService, ClusterService, TaskService)
- Move types to spore/types/ (NodeInfo, ApiTypes, Config)
- Move internal components to spore/internal/ (Globals)
- Update all #include statements to use new namespace paths
- Update platformio.ini build filters for all environments
- Update all example files to use new include paths
- Maintain backward compatibility for public API
- Improve code organization, maintainability, and scalability

This reorganization follows modern C++ project structure patterns and provides
clear separation between public API, internal implementation, and utilities.
All examples compile successfully with the new structure.

include/spore/core/NodeContext.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <WiFiUdp.h>
+#include <map>
+#include "spore/types/NodeInfo.h"
+#include <functional>
+#include <string>
+#include <initializer_list>
+#include "spore/types/Config.h"
+#include "spore/types/ApiTypes.h"
+
+class NodeContext {
+public:
+    NodeContext();
+    NodeContext(std::initializer_list<std::pair<String, String>> initialLabels);
+    ~NodeContext();
+    WiFiUDP* udp;
+    String hostname;
+    IPAddress localIP;
+    NodeInfo self;
+    std::map<String, NodeInfo>* memberList;
+    Config config;
+
+    using EventCallback = std::function<void(void*)>;
+    std::map<std::string, std::vector<EventCallback>> eventRegistry;
+
+    void on(const std::string& event, EventCallback cb);
+    void fire(const std::string& event, void* data);
+};