shellui add all: install every component at once #54

Summary

Projects that want to own the whole library through the CLI have to add components one by one. An AI coding agent working in such a project also can't see what exists, and tends to write its own version of anything not yet installed.

Proposal

shellui add all installs every direct target. Open questions:

• Heavy optional components pull in NuGet packages: charts (Blazor-ApexCharts), data-table (System.Linq.Dynamic.Core), qr-code (QRCoder). Include them, or offer --except chart,qr-code or groups (shellui add all --without charts)?
• Print a summary of what was installed and skipped (already installed).