feat(assert): assert_true and assert_false accept a command with arguments

[Chemaclass]

🤔 Background

Related #994

assert_true test -d /tmp
assert_true grep -q foo ./file
assert_false test -d /nope

The argument used to be run as a single command word. Anything with arguments was looked up as a command whose name contained spaces — so the natural spelling was the broken one, and the workaround was an eval prefix nobody had documented until #993.

💡 Changes

Arguments are now passed through as arguments. Nothing is re-parsed, so a path containing a space survives — which the eval form cannot promise.

Additive by construction. With exactly one argument the old path runs unchanged, including the literal true/false/0/1 fast path and the eval prefix. Every existing call means what it meant. The literal check is guarded on argument count, because assert_true true --version is the command named true, not the boolean.

The exit code is captured with || exit_code=$? rather than a bare call — under --strict a failing command as a statement would abort the whole test.

🚫 Why not split the string instead

Splitting the single-argument form on whitespace would silently change what an existing string means, break arguments that legitimately contain spaces, and make the assertion sometimes-word-splitting. Passing real arguments needs no re-parsing at all.

✅ Verification

All eight shapes checked: literal true, literal 0, bare function, eval prefix, variadic, variadic with a space in a path, variadic assert_false, and true --version where the literal and the command collide.

5 new tests, RED first. make sa · make lint · bash build.sh bin -v → ✅ Build verified ✅ · 1713 sequential / 1672 parallel-simple-strict.