fix(build-program): the program's directory is made beside its per-configuration output; e2e 111 reads the new place

Author: Sunrisepeak

src/build/build_program.cppm

@@ -1497,7 +1497,10 @@ std::expected<void, std::string> run_build_program_impl(
     // the program's turn comes.
     if (mode == ProgramMode::Compile) programReport.reported = true;
 
-    fs::create_directories(outDir, ec);   // creates bdir too
+    // Both: the output directory is per configuration and need not lie
+    // below `bdir`, where the program binary and its cache are (D7).
+    fs::create_directories(bdir, ec);
+    fs::create_directories(outDir, ec);
     // #230: on Windows the capture_exec shell is cmd.exe, which can only launch
     // a PE by an executable extension — a bare `.bin` is not in PATHEXT and
     // fails to run. Name the compiled program `.exe` there; other platforms keep

tests/e2e/111_dep_build_mcpp.sh

@@ -80,8 +80,9 @@ after="$(find "$TMP/deplib" | sort)"
     diff <(echo "$before") <(echo "$after") || true
     echo "dependency root was written to"; exit 1; }
 
-# Artifacts live in the consuming project.
-find target/.build-mcpp/deps -name 'gen_dep.cpp' | grep -q . || {
+# Artifacts live in the consuming project: the program in .build-mcpp/deps,
+# its output in this configuration's directory (mcpp 2026.10.10.1+).
+find target/.build-mcpp/out -path '*deplib/gen_dep.cpp' | grep -q . || {
     echo "dep OUT_DIR generated file not in project tree"; exit 1; }
 
 echo "OK"