feat(init): remove init-time driver download flow

[zycgit]

• Remove the init-time MySQL driver download page, APIs, WebSocket, progress bus, and frontend component.
• Load the main datasource from the bundled mysql-connector-j 8.0.33 jar with isolated classloading.
• Add GlobalConfUtils.getTempData for the runtime driver cache.
• Make ResourceLoader and CgClassLoader closeable to release jar handles.
• Let PluginLoadHelper load by plugin file name and aggregate jars in plugin directories.
• Load the inner-website plugin during init mode and serve favicon resources.
• Fix the init-mode dmGlobalSettings route and public access.
• Fall back to the init page when full startup fails on database initialization.
• Add admin account configuration and apply it to seed and admin update logic.
• Improve the init confirmation page and clean stale public URLs and driver-download messages.

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