feat(llm-application-dev): modernize to LangGraph and latest models v2.0.0

- Migrate from LangChain 0.x to LangChain 1.x/LangGraph patterns
- Update model references to Claude 4.5 and GPT-5.2
- Add Voyage AI as primary embedding recommendation
- Add structured outputs with Pydantic
- Replace deprecated initialize_agent() with StateGraph
- Fix security: use AST-based safe math instead of unsafe execution
- Add plugin.json and README.md for consistency
- Bump marketplace version to 1.3.3

plugins/llm-application-dev/.claude-plugin/plugin.json

@@ -0,0 +1,10 @@
+{
+  "name": "llm-application-dev",
+  "version": "2.0.0",
+  "description": "LLM application development with LangGraph, RAG systems, vector search, and AI agent architectures. Updated for LangChain 1.x, Claude 4.5, and GPT-5.2.",
+  "author": {
+    "name": "Seth Hobson",
+    "email": "seth@major7apps.com"
+  },
+  "license": "MIT"
+}