Add rtk cmake filter (collapse build progress, keep diagnostics)

Summary

Add an rtk cmake filter. cmake --build (and configure) output is verbose and dominated by progress/percentage lines that carry little signal once a build succeeds, but is a high-frequency command in C++ workflows.

Why

rtk discover flagged cmake as the #1 unhandled command in my history: 147 invocations over 30 days (e.g. cmake --build cmake-build-debug --target ...), with no RTK equivalent. C++ build/test loops run this constantly.

What's noisy

• [ NN%] Building CXX object ... progress lines (one per TU)
• Scanning dependencies of target ...
• Repeated make[1]/make[2] directory-entry chatter

Suggested behavior

• On success: collapse per-TU progress to a count (e.g. "Built N targets, M objects"), keep warnings/errors verbatim.
• On failure: preserve the failing compiler invocation + diagnostics in full; drop unrelated progress.
• Keep cmake configure output's cache/feature summary but drop the line-by-line check spam.