fix: bundle Windows runtime required at startup

[McanKul]

Root cause

The HEIC decoder added in v0.2.1 makes offpdf.exe import MSVCP140.dll. The Windows installer contained the Visual C++ runtime only under binaries/, but the Windows loader needs it beside offpdf.exe before any application code can run. Clean Windows machines therefore exited before opening a window.

Fix

• bundle MSVCP140 and its VCRUNTIME dependencies beside the main executable on Windows
• keep the resource mapping Windows-only so macOS builds remain portable
• install and launch the packaged NSIS application in CI before publishing
• prepare patch release v0.2.2

Validation

• frontend production build
• 21 frontend tests
• Rust check
• verified v0.2.1 executable imports MSVCP140.dll while installer placed it in the wrong directory
• packaged Windows launch smoke test (release workflow)