Clarify safe configuration ownership in READMEs

[denial123789]

Summary

• explain ownership-aware configuration updates and exact rollback in all three READMEs
• add a concise repository Star call-to-action after the quick start
• keep the localized pages aligned with English

Validation

• git diff --check
• npm test: build succeeds; 146 pass, 3 environment-dependent failures locally
  • two Kiro cases encounter the host's existing higher-priority ~/.kiro state
  • the MCP bridge integration test cannot bind 127.0.0.1 in the sandbox
• the ownership, JSONC preservation, and rollback claims are covered by the existing adapter tests

GitHub Actions should provide the authoritative clean-environment result.