chore: prepare v0.8.4 release

[MapleEve]

Summary

• prepare VoScript v0.8.4 release metadata and public changelog sections
• align public configuration/security docs with the v0.8.4 release surface
• keep OpenAPI version tests tied to the configured app version
• remove internal review markers from the public Dockerfile comment while preserving the reproducible-build guidance

Validation

• python voscript-api/scripts/public_release_scan.py --root .
• ruff check app/ --ignore E501 && ruff format --check app/
• PYTEST_DISABLE_PLUGIN_AUTOLOAD=1 python -m pytest tests/unit/ tests/test_security.py tests/test_voiceprint_db.py tests/test_job_service.py -q --tb=short
• cargo fmt --check && cargo test -p voscript_core

Notes

• Local Docker daemon was not running, so the release PR security-scan job remains the authoritative Python 3.11 pip-audit gate.
• Release validation details are described only as internal live validation categories; no private paths, sample names, job IDs, speaker IDs, hosts, logs, keys, or tokens are included.

[github-actions]

👍 @MapleEve

Thank you for raising your pull request and contributing to VoScript.
Please make sure you have followed our contributing guidelines. We will review it as soon as possible.
If you encounter any problems, please feel free to connect with us.
非常感谢您提出拉取请求并为 VoScript 做出贡献，请确保您已经遵循了我们的贡献指南，我们会尽快审查它。
如果您遇到任何问题，请随时与我们联系。

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.90%. Comparing base (49a9b63) to head (4e15a52).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #41   +/-   ##
=======================================
  Coverage   90.90%   90.90%           
=======================================
  Files          84       84           
  Lines        3696     3696           
=======================================
  Hits         3360     3360           
  Misses        336      336           

Flag	Coverage Δ
unit	90.90% <100.00%> (ø)

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[Copilot]

Pull request overview

Prepares the VoScript v0.8.4 release by bumping the configured app version, aligning public docs/changelogs with that release surface, and making the OpenAPI version test track the configured version constant instead of a hardcoded value.

Changes:

• Bumped APP_VERSION to 0.8.4 and updated the OpenAPI version unit test to assert against the configured version.
• Updated public security/configuration docs to reference v0.8.4 and added v0.8.4 validation wording sections.
• Added v0.8.4 changelog sections and cleaned up the public Dockerfile reproducible-build comment.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tests/unit/test_main_lifespan.py	Updates OpenAPI version assertion to use the configured app version constant.
doc/security.zh.md	Updates the documented “current version” for built-in hardening to 0.8.4.
doc/security.en.md	Updates the documented “as of” version for built-in hardening to 0.8.4.
doc/configuration.zh.md	Updates version references to 0.8.4 and adds v0.8.4 validation wording section.
doc/configuration.en.md	Updates version references to 0.8.4 and adds v0.8.4 validation wording section.
doc/changelog.zh.md	Adds “no unreleased changes” and a new 0.8.4 section (with dated heading).
doc/changelog.en.md	Adds “no unreleased changes” and a new 0.8.4 section (with dated heading).
app/Dockerfile	Removes internal review markers from the reproducible-build guidance comment.
app/config.py	Bumps APP_VERSION to 0.8.4.

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[github-actions]

❤️ Great PR @MapleEve ❤️

The growth of the project is inseparable from user feedback and contribution. Thanks for your contribution!
项目的成长离不开用户反馈和贡献，感谢您的贡献!