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/LoadedPlugin.java

@@ -0,0 +1,9 @@
+package me.neurodock.plugin;
+
+public record LoadedPlugin(
+        Plugin plugin,
+        ClassLoader loader,
+        PluginMetadata metaData
+) {
+
+}