chore: improve discoverability — keywords, badges, engines

- Add npm keywords: model-context-protocol, copilot, long-term-memory,
  llm-memory, rag, ai, llm, sqlite, local-ai, privacy, offline
- Add engines.node >= 18 (enables node version badge)
- Add README badges: npm downloads, license, node version

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: BrainSlugs83

README.md

@@ -2,6 +2,9 @@
 
 [![CI](https://github.com/BrainSlugs83/GithubCopilotCLI-VectorMemoryMCP/actions/workflows/ci.yml/badge.svg)](https://github.com/BrainSlugs83/GithubCopilotCLI-VectorMemoryMCP/actions/workflows/ci.yml)
 [![npm version](https://img.shields.io/npm/v/ghcp-cli-vector-memory-mcp)](https://www.npmjs.com/package/ghcp-cli-vector-memory-mcp)
+[![npm downloads](https://img.shields.io/npm/dm/ghcp-cli-vector-memory-mcp)](https://www.npmjs.com/package/ghcp-cli-vector-memory-mcp)
+[![license](https://img.shields.io/npm/l/ghcp-cli-vector-memory-mcp)](LICENSE)
+[![node](https://img.shields.io/node/v/ghcp-cli-vector-memory-mcp)](package.json)
 
 An [MCP](https://modelcontextprotocol.io/) server that adds **persistent long-term memory** to [**GitHub Copilot CLI**](https://docs.github.com/en/copilot/github-copilot-in-the-cli) via local semantic vector search. Copilot can recall past conversations, code changes, and decisions across all sessions — by meaning, not just keywords.
 

package.json

@@ -15,6 +15,9 @@
     "LICENSE",
     "README.md"
   ],
+  "engines": {
+    "node": ">=18"
+  },
   "type": "module",
   "license": "MIT",
   "homepage": "https://github.com/BrainSlugs83/GithubCopilotCLI-VectorMemoryMCP#installation",
@@ -25,16 +28,26 @@
   "keywords": [
     "mcp",
     "mcp-server",
+    "model-context-protocol",
     "github-copilot",
     "github-copilot-cli",
     "copilot-cli",
+    "copilot",
     "vector-search",
     "semantic-search",
     "memory",
+    "long-term-memory",
+    "llm-memory",
     "embeddings",
     "session-history",
     "onnx",
-    "model-context-protocol"
+    "rag",
+    "ai",
+    "llm",
+    "sqlite",
+    "local-ai",
+    "privacy",
+    "offline"
   ],
   "scripts": {
     "lint": "eslint index.js vector-memory-server.js embed-worker.js lib.js",