fix(e2e/ci): run msvc detection assertions from a neutral cwd

toolchain list stars the *effective* default; the repo root's mcpp.toml
[toolchain] windows=llvm@20.1.7 would shadow the freshly-set global
msvc@system when run_all.sh executes from the workspace.

Author: Sunrisepeak

.github/workflows/ci-windows.yml

@@ -238,6 +238,10 @@ jobs:
         run: |
           export MCPP_VENDORED_XLINGS="$XLINGS_BIN"
 
+          # Neutral cwd: the repo root's mcpp.toml [toolchain] would shadow
+          # the global default in `toolchain list` / doctor output.
+          TMP=$(mktemp -d); cd "$TMP"
+
           out=$("$MCPP_SELF" toolchain default msvc); echo "$out"
           grep -q "Detected"     <<<"$out"
           grep -q "msvc@system"  <<<"$out"
@@ -249,7 +253,6 @@ jobs:
           grep -qi "msvc" doctor.txt
 
           # native cl.exe builds are gated with one owned message
-          TMP=$(mktemp -d); cd "$TMP"
           "$MCPP_SELF" new hello_msvc && cd hello_msvc
           set +e
           bout=$("$MCPP_SELF" build 2>&1); brc=$?

tests/e2e/95_msvc_system_toolchain.sh

@@ -26,6 +26,11 @@ restore() {
 }
 trap restore EXIT
 
+# Neutral cwd: `toolchain list` stars the *effective* default, and a project
+# mcpp.toml [toolchain] in the cwd (e.g. the mcpp repo root, where run_all.sh
+# executes) would shadow the global default we're about to set.
+cd "$TMP"
+
 # 1) switch to msvc: detect + identify + persist
 out=$("$MCPP" toolchain default msvc 2>&1) || { echo "FAIL: default msvc: $out"; exit 1; }
 [[ "$out" == *"Detected"* ]]     || { echo "FAIL: no Detected line: $out"; exit 1; }
@@ -54,7 +59,6 @@ out=$("$MCPP" toolchain install msvc 2>&1) \
     || { echo "FAIL: install msvc message: $out"; exit 1; }
 
 # 5) native cl.exe builds are gated with one owned message
-cd "$TMP"
 "$MCPP" new hello_msvc >/dev/null 2>&1
 cd hello_msvc
 rc=0; out=$("$MCPP" build 2>&1) || rc=$?