docs(hosting): document community kubernetes deployment

[mberlofa]

Description

Adds a short Kubernetes Hosting section immediately after Docker Hosting in the English, Simplified Chinese, Japanese, and Turkish READMEs, with matching table-of-contents entries. Existing Docker instructions and limitations are preserved.

The guide identifies the chart as community-maintained by HelmForge and uses the official SiYuan image. It covers installation, Secret-based access-code retrieval, HTTPS/WebSocket ingress, network policy, a single workspace writer, Recreate upgrade downtime, PVC retention, consistent backups, and the limits of Helm rollback.

I maintain the HelmForge chart; chart support remains with HelmForge. This follows the documentation contribution approved in #19343 (comment).

Type of change

• Text updates or new language additions

Validation

• Markdown lint passed for all four added sections; localized anchors and identical installation commands checked.
• Verified that all pre-existing README content remains unchanged.
• Installed the published chart 1.0.0 (official SiYuan v3.8.3) on local k3d: 10Gi RWO PVC bound, Helm installation completed, access-code retrieval and Service port-forward worked, native login reached the authenticated workspace, and boot progress reached 100.
• Only README files changed; no chart or application code changed.

Checklist

• I have performed a self-review of my own code.
• I have full rights to the submitted code and agree to license it under this project's AGPL-3.0 license.
• PR is submitted to the dev branch and has no merge conflicts.

[88250]

关联 #19513 ：请将中文 Kubernetes 部署章节中两处「访问授权码」统一为「锁屏密码」，「该授权码」也改为「该密码」，与当前界面及现有 Docker 部署文档保持一致。Secret 的 access-code 键和 --accessAuthCode 参数名保持不变。用户指南中的对应旧术语已在主仓库修正。

[TCOTC]

@88250 让 AI 直接改了提交

[88250]

@88250 让 AI 直接改了提交

稍后在 #19513 中提交