Release ToolKnit Desktop v2.3.0

[ZihangDong]

Summary

• add Teleprompter, PDF Page Numbers, PDF Crop, Background Removal, and Excel to PDF
• harden update checks, WebView2 bootstrap, dependency installation, administrator relaunch, PDF compatibility, rounded-corner rendering, and shared tool navigation
• align the desktop app, Tauri bundle, Rust crate, CLI/MCP, release notes, and bilingual README on version 2.3.0
• keep the desktop catalog at 65 tools across 12 categories and the published CLI/MCP contract at 46 capabilities

Release validation

• npm run test:release: 60 scripts passed
• cargo test --locked: 87 passed, 0 failed, 1 environment-gated LibreOffice QA test ignored
• npm audit: 0 vulnerabilities
• cargo audit: no denied vulnerability, unsoundness, or yanked advisories; 16 allowed indirect maintenance warnings
• npm publish --dry-run --access public: 107 files, 19,801,282 packed bytes
• repository and npm package secret-signature scans passed

Release notes

• docs/desktop-update.md
• toolknit-desktop/CHANGELOG.md