fix(ci): resolve build failures across all platforms

- macOS: use `sed -i ''` (BSD sed requires empty extension arg)
- Linux: add `#include <limits.h>` to xdiff/git-compat-util.h for CHAR_BIT
- Windows Qt 6.5: add missing `#include <QGuiApplication>` in BranchPickerPopup
- Windows Qt 6.10: fix forward-decl mismatch (class→struct) for GitCommitInfo

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: nullmastermind

.github/workflows/build.yml

@@ -31,7 +31,11 @@ jobs:
         shell: bash
         run: |
           VER="${GITHUB_REF_NAME#v}"
-          sed -i 's/^\([[:space:]]*VERSION[[:space:]]*\).*/\1'"$VER"'/' CMakeLists.txt
+          if [[ "$OSTYPE" == darwin* ]]; then
+            sed -i '' 's/^\([[:space:]]*VERSION[[:space:]]*\).*/\1'"$VER"'/' CMakeLists.txt
+          else
+            sed -i 's/^\([[:space:]]*VERSION[[:space:]]*\).*/\1'"$VER"'/' CMakeLists.txt
+          fi
           grep -n '^[[:space:]]*VERSION' CMakeLists.txt
 
       - name: Install Qt

src/git/BranchPickerPopup.cpp

@@ -18,6 +18,7 @@
 
 #include "BranchPickerPopup.h"
 
+#include <QGuiApplication>
 #include <QKeyEvent>
 #include <QLineEdit>
 #include <QListView>

src/git/GitHistoryView.h

@@ -72,7 +72,7 @@ class GitHistoryView : public QWidget
     void keyPressEvent(QKeyEvent *event) override;
 
 private slots:
-    void onCommitsAppended(const QVector<class GitCommitInfo> &chunk);
+    void onCommitsAppended(const QVector<struct GitCommitInfo> &chunk);
     void onFetchStarted();
     void onFetchFinished(bool reachedEnd, const QString &errorMessage);
     void onRowActivated(const QModelIndex &index);

thirdparty/xdiff/git-compat-util.h

@@ -12,6 +12,7 @@
 #define GIT_COMPAT_UTIL_H
 
 #include <ctype.h>
+#include <limits.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>