chore: update package version to 1.2.5 and add Jest testing framework

- Bump version in package.json and package-lock.json from 1.2.2 to 1.2.5
- Add Jest configuration file for testing
- Update build scripts to use npm instead of bun
- Add linting and testing scripts to package.json
- Include tsconfig files in package.json files array

.claude/settings.local.json

@@ -7,7 +7,11 @@
       "Bash(npm test:*)",
       "Bash(npm install:*)",
       "Bash(npm run build:*)",
-      "Bash(bun:*)"
+      "Bash(bun:*)",
+      "Bash(rm:*)",
+      "Bash(del \"D:\\Git\\ssr-project\\mxrelay-consumer\\bun.lock\")",
+      "Bash(npm run lint)",
+      "Bash(npm publish:*)"
     ],
     "deny": [],
     "ask": []