feat(npm): enhance .npmignore and add prepublish check script

Updated .npmignore to include sensitive files such as .env and key files, ensuring they are excluded from npm packages. Introduced a new script, check-pack.ts, to validate that no sensitive files are included in the npm tarball before publishing. Updated package.json to include the new script in the prepublish process and expanded the files whitelist for packaging.

package.json

@@ -11,6 +11,19 @@
   "bin": {
     "ritmex-bot": "./bin/ritmex-bot"
   },
+  "files": [
+    "bin",
+    "src",
+    "scripts",
+    "index.ts",
+    "tsconfig.json",
+    "setup.sh",
+    ".env.example",
+    "README_en.md",
+    "cli-guide.md",
+    "cli-guide.en.md",
+    "grid-trading.md"
+  ],
   "scripts": {
     "dev": "bun run index.ts",
     "start": "bun run index.ts",
@@ -20,6 +33,8 @@
     "test": "bun x vitest run",
     "test:exchange-contract": "bun x vitest run tests/exchange-contract-suite.test.ts tests/exchange-factory.test.ts tests/config.test.ts",
     "test:watch": "bun x vitest",
+    "check:pack": "bun run scripts/check-pack.ts",
+    "prepublishOnly": "bun run scripts/check-pack.ts",
     "start:trend:silent": "bun run index.ts --strategy trend --silent",
     "start:maker:silent": "bun run index.ts --strategy maker --silent",
     "start:offset:silent": "bun run index.ts --strategy offset-maker --silent",