feat(plugin): scaffold RPCP plugin loading core

- Add JarFile-based plugin.json manifest reading and validation
- Implement reflection-based plugin class instantiation (Data or no-arg constructor)
- Wrap Tool objects into OllamaFunctionTool with basic parameter/response handling
- Implement ToolArguments storage and ToolResponse record
- Extract RPCP_SOURCE constant; add plugin name validation
- Update Data interface: getLoadedPlugins() returns LoadedPlugin[]
- Fix launcher package references (me.zacharias.chat → me.neurodock)

TODO: Extract FileSystem from JAR, populate PluginMetadata, complete
OllamaFunctionArgument↔ToolArguments wrapping, invoke plugin lifecycle hooks

Signed-off-by: zacharias <alienfromdia@proton.me>

Plugin-API/src/main/java/me/neurodock/plugin/Data.java

@@ -4,6 +4,6 @@ import java.io.File;
 
 public abstract class Data {
     public abstract File getDataDictionary();
-    public abstract LoadedPlugins getLoadedPlugins();
+    public abstract LoadedPlugin[] getLoadedPlugins();
     public abstract File getCacheDirectory();
 }