Fix Windows toolbar and Winget distribution

[Redth]

Windows users currently see generic circle glyphs for unmapped toolbar actions, while the Winget package installs only a portable command with no Start menu entry. Recent Winget manifests also stopped at fork branches because upstream PR creation depended on short-lived Microsoft SSO authorization.

Changes

• Render Windows toolbar actions as explicitly centered Fluent icon and text layouts, map all current toolbar symbols, and avoid bogus fallback glyphs.
• Preserve action enabled state and add readable labels such as Release Notes, New Folder, and Open Project Folder.
• Build self-contained x64 and ARM64 Inno Setup installers while retaining ZIP release assets for existing download and update flows.
• Register MAUI Sherpa in the Start menu with per-user installation and normal uninstall support.
• Publish Winget manifests against the new installers instead of portable ZIPs.
• Replace PAT-dependent upstream submission with a prominent, prefilled browser link in the Actions summary so the final PR uses the maintainer's browser session.

Validation

• Built and launched the Windows Release app and visually checked toolbar icon and label alignment.
• Launched the exact self-contained publish output without DOTNET_ROOT or a system .NET 10 runtime.
• Compiled x64 and ARM64 installers and confirmed the Start menu shortcut is created and removed through install/uninstall.
• Generated and validated the updated Winget manifests.