Add project website and automated releases

[Harukafly]

What changed

• adds a responsive bilingual GitHub Pages site with direct downloads, feature explanations, privacy details, SEO metadata, a sitemap, and no analytics
• adds a clear 1280×720 Ghost demo with privacy-safe product data
• adds a Windows x64 build workflow with self-test, startup smoke test, checksums, artifacts, and tag-based GitHub Release publishing
• fixes the local Release build script so failed CMake commands cannot be reported as successful
• links the website from the README

Validation

• clean Visual Studio 2022 x64 Release build
• Peek self-test: Ghost, Unlock, Focus, and EventStore all passed
• startup smoke test passed
• desktop and mobile site layouts checked locally
• Chinese/English switching checked
• video loaded as 1280×720, 17.1 seconds, with no browser console errors
• final video keyframes checked for clarity and private/development-tool information