fix: avoid full rebuild by writing BuildVer.h only when content changes

Previously, prebuild.ps1 unconditionally overwrote BuildVer.h on every
build using Set-Content, updating its timestamp even when the content
was identical. This caused MSBuild to treat all files depending on
BuildVer.h as out of date, triggering a full rebuild every time.

Fix: compare the new content with the existing file before writing.
BuildVer.h is now only written if sha, branch, or dev suffix has
actually changed.

Also removed the `git restore` call from postbuild.ps1 as it is no
longer needed.

Minecraft.Client/postbuild.ps1

@@ -36,8 +36,6 @@ foreach ($copy in $copies) {
 
     if (Test-Path $src) {
         # Copy the files using xcopy, forcing overwrite and suppressing errors, and only copying if the source is newer than the destination
-		xcopy /q /y /i /s /e /d "$src" "$dst" 2>$null
+        xcopy /q /y /i /s /e /d "$src" "$dst" 2>$null
     }
-}
-
-git restore "**/BuildVer.h"
+}

Minecraft.Client/prebuild.ps1

@@ -27,7 +27,7 @@ if (git status --porcelain) {
     $suffix = "-dev"
 }
 
-@"
+$newContent = @"
 #pragma once
 
 #define VER_PRODUCTBUILD $build
@@ -35,4 +35,14 @@ if (git status --porcelain) {
 #define VER_FILEVERSION_STR_W VER_PRODUCTVERSION_STR_W
 #define VER_BRANCHVERSION_STR_W L"$ref"
 #define VER_NETWORK VER_PRODUCTBUILD
-"@ | Set-Content "Common/BuildVer.h"
+"@
+
+$path = "Common/BuildVer.h"
+$existing = if (Test-Path $path) { Get-Content $path -Raw } else { "" }
+
+if ($existing.Trim() -ne $newContent.Trim()) {
+    $newContent | Set-Content $path
+    Write-Host "BuildVer.h aggiornato."
+} else {
+    Write-Host "BuildVer.h invariato, skip."
+}