chore: bump version to 2.8.3 and update changelog

- Updated version in package.json and package.runtime.json
- Updated version badge in README.md
- Added comprehensive changelog entry for v2.8.3
- Fixed TypeScript lint errors in test files by making env vars optional
- Fixed edge-cases test to include required NODE_ENV

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

tests/unit/docker/edge-cases.test.ts

@@ -422,7 +422,7 @@ describe('Docker Config Edge Cases', () => {
       // We need to preserve PATH so node can be found
       const output = execSync(`node "${parseConfigPath}" "${configPath}"`, { 
         encoding: 'utf8',
-        env: { PATH: process.env.PATH } // Only include PATH
+        env: { PATH: process.env.PATH, NODE_ENV: 'test' } // Only include PATH and NODE_ENV
       });
       
       // Verify all configuration is properly exported with export prefix