docs: update Chinese README for Attu v3.0

[shanghaikid]

The Chinese README still described Attu v2.6, including obsolete environment variables, screenshots, and browser-local configuration storage. Update it to match the public v3.0 English README and published release assets.

• Cover v3.0 features, compatibility, screenshots, server packages, local login, audit logs, and TLS configuration.
• Correct Docker persistence and networking guidance, Kubernetes deployment links and access instructions, and SQLite backup guidance.
• Link Compose users to the complete official Milvus deployment and provide an Attu service to add to its network. Use the published server launcher for administrator examples.
• Replace the self-referencing language badge with an English link and remove stale navigation and unsupported platform requirements.

Validation: checked all 13 local document/image references, Bash syntax for all 12 shell examples, coverage of all 31 configuration variables in the English README, release asset names, DCO sign-off, and git diff --check. Documentation-only change; deployment examples were not executed.