Make Windows Terminal the default terminal

[daxgames]

Summary

This PR makes Windows Terminal the default terminal for Cmder and refactors the packaging flow around terminal profiles.

What changed

• Adds scripts/package-profiles.json to define package profiles for Windows Terminal, ConEmu, and a no-emulator build.
• Updates scripts/build.ps1 and scripts/pack.ps1 to accept a -Terminal parameter and build only the selected profile set.
• Adds shared helpers in scripts/utils.ps1 to resolve package profiles and exclusions.
• Updates .github/workflows/build.yml to build and package all profiles in CI and summarize the produced artifacts.
• Refreshes scripts/README.md with the new -Terminal usage and profile-based examples.

Notes

• The Windows Terminal profile is now the default build path.
• The no-emulator package is kept as a separate option for users who want Cmder as a shell profile in another terminal.