fix: Windows E2E — double-quote git paths, enable fresh-sandbox, untag test 27

- cli.cppm: wrap git clone commands in #if _WIN32 guards to use double
  quotes instead of single quotes (cmd.exe doesn't understand POSIX
  single-quoting)
- run_all.sh: add fresh-sandbox to CAPS on MINGW/MSYS/CYGWIN so tests
  02, 24, and 32 run on Windows
- 27_self_contained_home.sh: drop 'elf' from requires tag — the test
  only exercises filesystem layout and env-var resolution via
  GetModuleFileNameA (already ported), no ELF-specific behaviour

Author: Sunrisepeak

src/cli.cppm

@@ -1959,15 +1959,28 @@ prepare_build(bool print_fingerprint,
                     std::format("{} ({} = {})", spec.git, spec.gitRefKind, spec.gitRev));
                 std::string cloneCmd;
                 if (spec.gitRefKind == "branch") {
+#if defined(_WIN32)
+                    cloneCmd = std::format(
+                        "git clone --depth 1 --branch \"{}\" \"{}\" \"{}\" 2>&1",
+                        spec.gitRev, spec.git, gitRoot.string());
+#else
                     cloneCmd = std::format(
                         "git clone --depth 1 --branch '{}' '{}' '{}' 2>&1",
                         spec.gitRev, spec.git, gitRoot.string());
+#endif
                 } else {
                     // For tag/rev: full clone, then checkout (depth-1 may miss the rev).
+#if defined(_WIN32)
+                    cloneCmd = std::format(
+                        "git clone \"{}\" \"{}\" && cd \"{}\" && git checkout --quiet \"{}\" 2>&1",
+                        spec.git, gitRoot.string(),
+                        gitRoot.string(), spec.gitRev);
+#else
                     cloneCmd = std::format(
                         "git clone '{}' '{}' && cd '{}' && git checkout --quiet '{}' 2>&1",
                         spec.git, gitRoot.string(),
                         gitRoot.string(), spec.gitRev);
+#endif
                 }
                 std::string out;
                 {

tests/e2e/27_self_contained_home.sh

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# requires: elf
+# requires:
 # 27_self_contained_home.sh — verifies mcpp's self-contained home behaviour.
 #
 # Without MCPP_HOME set, mcpp resolves its home from the binary's location:

tests/e2e/run_all.sh

@@ -69,6 +69,7 @@ case "$OS" in
         fi
         # NOTE: Windows runners may have g++.exe (MinGW/Strawberry) in PATH
         # but it's not a proper mcpp-compatible GCC. Don't add gcc capability.
+        CAPS+=(fresh-sandbox)
         ;;
 esac