test runner, cross-target runners, lib/exe split

- subprocess-isolated test runner (replaces V1 dlopen-RunTest);
  Pass/Fail/Crash/Timeout/Skipped outcomes via :Test partition
- TestRunner abstraction with command templates: Local, Ssh,
  SshWin (cmd.exe-shell), QemuUser, FromEnv; probe-based skip
  when runner unreachable
- transitive PCM-path propagation in Build(); resolveImport
  walks deps recursively; depResults cache keyed by PcmDir()
  so per-target builds don't collide
- cfg.sysroot threaded through BuildStdPcm + base compile/link
  command (enables aarch64 cross via Arch Linux ARM rootfs)
- lib + exe split: project.cpp defines crafterBuildLib
  (LibraryStatic) + crafterBuildExe (Executable depending on
  it); build.sh produces lib/libcrafter-build.a alongside
  bin/crafter-build for downstream static-link consumers
- Windows DLL+launcher: CRAFTER_API macro, /EXPORT flag for
  project.dll's CrafterBuildProject; Crafter::Run as the real
  entry point with main.cpp as a thin wrapper
- 18 tests: HelloWorld/WithModule/Defines/CrossProjectModule/
  Diamond × (Linux + sshwin:winvm), plus Incremental,
  BuildError, Libraries, RunnerClassification, QemuUser,
  SshRunner, WindowsViaSsh, CrossArchAarch64
- single ./bin/crafter-build test runs everything; Windows
  variants skip gracefully if winvm SSH alias unreachable

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tests/RunnerClassification.cpp

@@ -0,0 +1,61 @@
+/*
+Crafter® Build
+Copyright (C) 2026 Catcrafts®
+Catcrafts.net
+
+LGPL-3.0-only.
+*/
+
+import std;
+#include "TestUtil.h"
+namespace fs = std::filesystem;
+using namespace TestUtil;
+
+namespace {
+    bool Contains(std::string_view haystack, std::string_view needle) {
+        return haystack.find(needle) != std::string_view::npos;
+    }
+}
+
+int main() {
+    try {
+        fs::path projectRoot = fs::current_path();
+        fs::path src = projectRoot / "tests" / "fixtures" / "runner-classification";
+        fs::path crafterBuild = projectRoot / "bin" / "crafter-build";
+
+        fs::path work = CopyFixtureToTemp("RunnerClassification", src);
+
+        // Run the inner crafter-build test with a short timeout for the Hang test.
+        auto run = RunInDir(work, std::format("'{}' test --timeout=2", crafterBuild.string()));
+
+        // Inner runner must report 1 passed + 1 failed + 1 crashed + 1 timed out.
+        // Therefore exit code must be nonzero.
+        if (run.exitCode == 0) {
+            std::println(std::cerr, "inner runner unexpectedly succeeded:\n{}", run.output);
+            return 1;
+        }
+
+        struct Check { std::string_view name; std::string_view marker; };
+        Check checks[] = {
+            {"Pass",    "\xE2\x9C\x85 Pass"},               // ✅ Pass
+            {"Fail",    "\xE2\x9D\x8C Fail"},               // ❌ Fail
+            {"Crash",   "Crash"},                            // any line mentioning Crash
+            {"crashed", "crashed:"},                         // crash classifier line
+            {"Hang",    "Hang"},                             // any line mentioning Hang
+            {"timeout", "timeout"},                          // timeout classifier word
+            {"summary", "1 passed, 1 failed, 1 crashed, 1 timed out"},
+        };
+
+        for (auto& c : checks) {
+            if (!Contains(run.output, c.marker)) {
+                std::println(std::cerr, "expected marker {:?} ({}) not found in inner output:\n{}",
+                    c.marker, c.name, run.output);
+                return 1;
+            }
+        }
+        return 0;
+    } catch (const std::exception& e) {
+        std::println(std::cerr, "test exception: {}", e.what());
+        return 1;
+    }
+}