fix: repair POSIX build and unpin the CI Visual Studio generator

process_posix.cpp: Process::wait_for was defined inside Process::wait(), before
that function's trailing throw, so every POSIX build failed with "function
definition is not allowed here". This translation unit is not compiled on
Windows, which is why it went unnoticed. Move wait_for out to file scope.

ci.yml: drop the hardcoded -G "Visual Studio 17 2022". The windows-latest runner
image no longer ships that toolchain ("could not find any instance of Visual
Studio"), failing the Windows job at configure regardless of the code. CMake's
per-platform default generator is correct on all three runners.

Author: 0xeb

.github/workflows/ci.yml

@@ -12,21 +12,17 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
-        include:
-          - os: ubuntu-latest
-            cmake_generator: "Unix Makefiles"
-          - os: windows-latest
-            cmake_generator: "Visual Studio 17 2022"
-          - os: macos-latest
-            cmake_generator: "Unix Makefiles"
 
     runs-on: ${{ matrix.os }}
 
     steps:
       - uses: actions/checkout@v4
 
       - name: Configure CMake
-        run: cmake -B build -G "${{ matrix.cmake_generator }}" -DCMAKE_BUILD_TYPE=Release -DCOPILOT_BUILD_TESTS=ON
+        # Deliberately no -G: runner images rotate their Visual Studio version, and pinning
+        # one ("Visual Studio 17 2022") breaks the Windows job the moment the image moves on.
+        # CMake's per-platform default is correct on all three runners.
+        run: cmake -B build -DCMAKE_BUILD_TYPE=Release -DCOPILOT_BUILD_TESTS=ON
 
       - name: Build
         run: cmake --build build --config Release

src/process_posix.cpp

@@ -587,21 +587,21 @@ int Process::wait()
         return handle_->exit_code;
     }
 
-    std::optional<int> Process::wait_for(std::chrono::milliseconds timeout)
-    {
-        const auto deadline = std::chrono::steady_clock::now() + timeout;
-        do
-        {
-            if (auto result = try_wait())
-                return result;
-            std::this_thread::sleep_for(std::chrono::milliseconds(10));
-        } while (std::chrono::steady_clock::now() < deadline);
-        return std::nullopt;
-    }
-
     throw ProcessError("waitpid failed: " + get_errno_message());
 }
 
+std::optional<int> Process::wait_for(std::chrono::milliseconds timeout)
+{
+    const auto deadline = std::chrono::steady_clock::now() + timeout;
+    do
+    {
+        if (auto result = try_wait())
+            return result;
+        std::this_thread::sleep_for(std::chrono::milliseconds(10));
+    } while (std::chrono::steady_clock::now() < deadline);
+    return std::nullopt;
+}
+
 void Process::terminate()
 {
     if (handle_ && handle_->pid > 0 && handle_->running)