docs: polish post-launch repository and Chinese localization

[XiaojuCH]

Summary

• update public-facing README facts for the post-launch repository, add one CI badge, and document the v0.1 same-installation/same-principal comparison boundary
• integrate and polish the Simplified Chinese README while preserving commands, scope, product status, and the security boundary
• update security reporting to use the enabled GitHub Private Vulnerability Reporting channel
• state honestly that no dedicated private Code of Conduct reporting channel is currently published
• refresh durable project state for the public repository, passing CI, enabled security features, active main ruleset, and pre-collector hardening phase

Validation

• git diff --check
• relative Markdown link target check for all modified files
• README command and factual parity review
• stale pre-launch wording and fake-contact check
• cargo fmt --all --check
• cargo clippy --locked --workspace --all-targets -- -D warnings
• cargo test --locked --workspace --all-targets (21 passed)
• existing CLI fixture/status smoke commands
• independent reviewer: no high- or medium-severity findings

Scope

Documentation and repository presentation only. No product/runtime behavior, Rust source, schema, tests, fixtures, Cargo manifests, CI workflow behavior, or GitHub ruleset changed.