[julian-goldstein]

Summary

Checklist build output (build/ui.mk), replacing the cargo-style verb column from #38/#39:

● toolchain  v0.10.1  ~/.local/share/yeet/toolchain/linux/x86_64/v0.10.1
✔ vmlinux.h  src/bpf/include/vmlinux.h
✔ cpusched   .build/bpf/cpusched.bpf.o
✔ runqlat    .build/bpf/runqlat.bpf.o
✔ link       bin/probe.bpf.o
✔ bundle     dist/index.js
✔ done       myproject (0.66s)

==> bin/probe.bpf.o (7.9kb)
==> dist/index.js (15.5kb)

• One row per step: green check, cyan tag, the artifact it produced. A yellow braille spinner animates the row while the step runs (terminal + serial builds only; -j keeps static rows), with the command's output captured and replayed above the finished row, so a compiler error still lands right before its red ✘ … (failed) row.
• done row with the total build time; artifacts listed below as bold ==> path (size), path magenta, size bold green.
• Commands hidden, make V=1 echoes each one before its row. Color only when stderr is a tty, TERM != dumb, NO_COLOR unset. Marks and spinner fall back to ASCII outside a UTF-8 locale. make clean prints one row per removed path.
• scripts/new prints in the same style, without make's directory banner, and its next-step hint says make (there is no yeet build). The C locale it forced is now scoped to the name check so the marks match.

Bundle is dist/index.js. index.js is on yeet's entry ladder and src/main.jsx mounts its root explicitly, so the .jsx extension carried no meaning. Verified by running the app under a pty with both names.

bin/ is a build product. template/bin/.gitkeep removed, /bin/ ignored wholesale, make clean removes it, the bin rule recreates it. A fresh scaffold has no bin/ until built, and git status is clean after a build-then-clean cycle.

Kernel matrix stages veristat in .kmatrix/ (its own, gitignored workspace) instead of bin/: build/kernel-matrix.sh (which now creates .kmatrix/ before staging rather than wiping it afterwards), build/verify-kernel.sh's default path, and .github/workflows/kernel-matrix.yml.

Upstream note: toolchain.mk and fetch-toolchain.sh are embed glue; the changes are mirrored into toolchain/embed/ here and still need a PR in yeet-src/toolchain before the next make sync-toolchain.

Test plan

• Fresh scaffold: tty output (spinner frames, clears, final rows), piped plain output, V=1, deliberate compile error, make -j4 (no spinner), LC_ALL=C ASCII fallback.
• yeet run . starts the TUI from dist/index.js under a pty.
• No bin/ before the first build; removed by make clean; clean git status after build + clean in a committed scaffold.
• scripts/new output on a tty and piped; invalid names still rejected.
• sh -n on both kernel-matrix scripts; no bin/veristat references remain.
• make veristat-matrix and the CI kernel-matrix workflow (boot VMs; not run).