feat: add node help system and registry for extensible node types

- Implemented a help system for different node types (config, render, variable, function) with detailed usage instructions.
- Created a node registry to manage node types, including registration, retrieval, and validation of connections between nodes.
- Defined central node and edge types for the application to streamline state management.
- Added Nunjucks autocomplete functionality to enhance user experience in template editing.
- Developed a syntax highlighting parser for PlantUML and Nunjucks within the CodeMirror editor.
- Registered built-in node types at application startup, including their default configurations and help entries.
- Introduced a theme context provider to manage light/dark mode preferences across the application.
- Created utility functions for class name management using clsx and tailwind-merge.
- Set up Tailwind CSS for styling with custom themes and responsive design.
- Configured Vite for development with proxy settings for backend API calls and Kroki diagram service.

.vite/deps/_metadata.json

@@ -0,0 +1,8 @@
+{
+  "hash": "dba24d0a",
+  "configHash": "beca0bba",
+  "lockfileHash": "85459ac0",
+  "browserHash": "3fd5087e",
+  "optimized": {},
+  "chunks": {}
+}

.vite/deps/package.json

@@ -0,0 +1,3 @@
+{
+  "type": "module"
+}