docs: update npm commands to bun in README and documentation files

- Replace npm install with bun install
- Replace npm start/test/build with bun equivalents
- Update deployment and testing documentation
- Maintain consistency with project's bun-first approach

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Co-Authored-By: AI Assistant <noreply@ai-assistant.com>

deploy/README.md

@@ -33,6 +33,7 @@ deploy/
 - Docker with buildx for multi-arch builds
 - kubectl CLI tool
 - Access to container registry (Docker Hub, GitHub Container Registry, or private registry)
+- Bun runtime for local development and testing
 
 ## Quick Start