fix(release): provide directly downloadable ZIP app packages (#391)

## Problem and outcome

App downloads used tar.gz archives, which are less convenient to open
with desktop file managers. Windows, macOS and Linux App packages now
ship as ZIP files. Packaging extracts the completed ZIP and runs the
existing runtime checks against those extracted files, covering the
actual distributed package.

The website links directly to the published ZIP for each platform, with
an explicitly labeled GitHub primary download and matching Gitee
alternative. Server deployment archives retain their existing format.

## Release notes

### 中文

- Windows、macOS 和 Linux 客户端改用 ZIP 压缩包，下载后可直接使用系统解压工具完整解压。
- 官网按系统提供 ZIP 直接下载和 Gitee 备用下载入口。

### English

- Windows, macOS and Linux App downloads now use ZIP archives for easier
extraction with desktop file managers.
- The website provides direct ZIP downloads for each platform, with
Gitee as an alternative download source.

## Verification

- `npm run check`: 58 test files / 760 tests, TypeScript and production
build passed.
- Real ZIP round-trip verification covers nested, hidden and Unicode
paths; Unix checks also verify executable modes and launch the extracted
fixtures. Windows archive checks passed locally; all three native
packaging runners execute the existing runtime checks from the final
extracted ZIP.
- Website build, release/mirror validation tests, documentation,
repository hygiene and diff checks passed.

## Impact

Compatible packaging change. Product behavior, protocols and existing
published release artifacts remain unchanged. The release pipeline
publishes a new patch version and refreshes website links after
publication.

.github/workflows/repository-hygiene.yml

@@ -168,10 +168,12 @@ jobs:
       # installed here too.
       - name: Install dependencies
         run: npm ci
-      - name: Install Linux native capture dependencies
+      - name: Install Linux packaging and native capture dependencies
         if: matrix.target == 'linux-amd64'
         run: >-
           sudo apt-get update && sudo apt-get install -y
+          zip
+          unzip
           libportal-dev
           libgstreamer1.0-dev
           libgstreamer-plugins-base1.0-dev