test(script): names, arguments and exit codes, in process and by CLI

RunScript on hand-built configurations: the named script alone runs,
with the project, the project directory and the arguments exactly as
given; its return value comes back whole from 0 to 255 and as 1 outside
that; a script that throws exits 1. A project without scripts, a
duplicate, an untypeable name, a missing callback and an unknown name
all fail without running anything. ctx.Run returns the command's exit
code and 128+signal for a killed one, and ShellQuote carries quotes,
spaces and expansions through sh intact.

Then the same through Run() with a fixture project, because the parsing
is where this goes wrong. `run record a --help -v clean --debug
--version run` must hand all seven words to the script, leave the one
project arg that stood before `run` alone, and not delete the staged
bin/ and build/. `run clean` and `run help` look for scripts of those
names. Moving the two capture branches below the verbs in the parse
loop fails this test.

The command-line half needs the installed module sources and is skipped
without them, but only when the in-process half reported no failure.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

project.cpp

@@ -152,6 +152,8 @@ extern "C" Configuration CrafterBuildProject(std::span<const std::string_view> a
             .LinkFlag("-Wl,--export-dynamic").LinkFlag("-ldl");
         cfg.AddTest("ProjectDependency").Dependencies({ CrafterBuildLib.get() })
             .LinkFlag("-Wl,--export-dynamic").LinkFlag("-ldl");
+        cfg.AddTest("Script").Dependencies({ CrafterBuildLib.get() })
+            .LinkFlag("-Wl,--export-dynamic").LinkFlag("-ldl");
         cfg.AddTest("ConcurrentDependencyReset").Dependencies({ CrafterBuildLib.get() });
         cfg.AddTest("Lint").Dependencies({ CrafterBuildLib.get() });
     }