build: remove legacy UpdateGameDlls target and simplify PS1 script

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

.gitignore

@@ -18,6 +18,3 @@ build/
 /*/package/*.zip
 /*/package/patchers/
 /*/package/plugins/
-
-# UpdateGameDlls build-time lock file (created by UpdateGameDlls.ps1)
-AssemblyFromGame/.update.lock

AGENTS.md

@@ -41,6 +41,7 @@ DSP_Mods/
 ├── PoolOpt/                  # Memory pool optimization on save loading
 ├── UniverseGenTweaks/        # Universe generator parameter tweaks
 ├── UserCloak/                # Hides/fakes Steam account info
+├── UpdateGameDlls/           # MSBuild helper project; runs UpdateGameDlls.ps1 before any mod compiles
 └── CompressSave/             # Stub only (moved to external repo)
 ```
 
@@ -70,35 +71,34 @@ DSP_Mods/
 
 Common properties and references are factored into two root-level files that MSBuild automatically imports for every project:
 
-- **`Directory.Build.props`** — shared `PropertyGroup` defaults (`TargetFramework`, `AllowUnsafeBlocks`, `LangVersion`, `RestoreAdditionalProjectSources`) and shared `ItemGroup`s (BepInEx packages, game DLL references, `Microsoft.NETFramework.ReferenceAssemblies`).
-- **`Directory.Build.targets`** — defines the `UpdateGameDlls`, `ZipMod`, and `CopyToParentPackage` targets (see below).
-- **`UpdateGameDlls.ps1`** — PowerShell script invoked by the `UpdateGameDlls` target; locates the DSP installation via Steam registry and `libraryfolders.vdf`, compares DLL timestamps, and re-publicizes stale DLLs using `assembly-publicizer`.
+- **`Directory.Build.props`** — shared `PropertyGroup` defaults (`TargetFramework`, `AllowUnsafeBlocks`, `LangVersion`, `RestoreAdditionalProjectSources`) and shared `ItemGroup`s (BepInEx packages, game DLL references, `Microsoft.NETFramework.ReferenceAssemblies`), and a global `ProjectReference` to the `UpdateGameDlls` helper project (ensuring game DLLs are refreshed before any mod project resolves assembly references).
+- **`Directory.Build.targets`** — defines the `ZipMod` and `CopyToParentPackage` targets (see below).
+- **`UpdateGameDlls.ps1`** — PowerShell script invoked by the `UpdateGameDlls` helper project; locates the DSP installation via Steam registry and `libraryfolders.vdf`, compares DLL timestamps, and re-publicizes stale DLLs using `assembly-publicizer`.
 
 Individual `.csproj` files only declare what is unique to that project (GUID, version, extra packages, embedded resources).
 
 ### Automatic Game DLL Update
 
-`AssemblyFromGame/` holds publicized copies of two game DLLs used as compile-time references. They are refreshed automatically **once per solution build** by the `UpdateGameDlls` MSBuild target, which calls `UpdateGameDlls.ps1`.
+`AssemblyFromGame/` holds publicized copies of two game DLLs used as compile-time references. They are refreshed automatically before any mod project compiles by the `UpdateGameDlls` helper project.
 
-The target runs only when the `UXAssist` project is being built (the designated trigger project), or when either DLL is missing from `AssemblyFromGame/`. This prevents redundant executions and file-write conflicts when projects are built in parallel (`dotnet build -m`). The PowerShell script additionally acquires an exclusive file lock (`AssemblyFromGame/.update.lock`) so that the rare case where the `!Exists` fallback triggers multiple projects concurrently is also handled safely.
+The helper project (`UpdateGameDlls/UpdateGameDlls.csproj`) uses the `Microsoft.Build.NoTargets` SDK and is declared as a global `ProjectReference` in `Directory.Build.props` with `ReferenceOutputAssembly=false`, `SkipGetTargetFrameworkProperties=true`, and `Private=false`. This ensures that MSBuild's dependency graph guarantees the helper project completes before any mod project resolves assembly references, with no need for file locks or conditional triggers.
 
-The script:
+The `UpdateGameDlls.ps1` script:
 1. Reads the Steam installation path from the Windows registry (`HKCU\Software\Valve\Steam`).
 2. Parses `steamapps/libraryfolders.vdf` to find the library that contains DSP (AppID `1366540`).
 3. Locates `<game_root>/DSPGAME_Data/Managed/`.
-4. Acquires an exclusive file lock on `AssemblyFromGame/.update.lock` (waits up to 60 s).
-5. For each DLL (`Assembly-CSharp.dll`, `UnityEngine.UI.dll`): if the game copy is newer than the local copy, runs `assembly-publicizer … --strip --overwrite` to regenerate the local file and stamps it with the source timestamp.
+4. For each DLL (`Assembly-CSharp.dll`, `UnityEngine.UI.dll`): if the game copy is newer than the local copy, runs `assembly-publicizer … --strip --overwrite` to regenerate the local file and stamps it with the source timestamp.
 
-The target can also be run explicitly:
+To explicitly update game DLLs:
 ```
-dotnet build -t:UpdateGameDlls
+dotnet build UpdateGameDlls\UpdateGameDlls.csproj
 ```
 
 **Prerequisite:** `assembly-publicizer` must be installed as a .NET global tool:
 ```
 dotnet tool install -g BepInEx.AssemblyPublicizer.Cli
 ```
-If the tool is missing or DSP is not found, the target prints a warning and continues without failing the build.
+If the tool is missing or DSP is not found, the script prints a warning and continues without failing the build.
 
 ### Packaging
 

Directory.Build.targets

@@ -1,39 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
-  <!--
-    UpdateGameDlls target: locates the Dyson Sphere Program installation via the
-    Steam registry and libraryfolders.vdf, then uses assembly-publicizer to
-    refresh AssemblyFromGame/ whenever the game DLLs are newer than the local copies.
-
-    Runs automatically before every build (BeforeTargets="BeforeBuild") and can
-    also be invoked explicitly:
-        dotnet build -t:UpdateGameDlls
-
-    Requires assembly-publicizer on PATH or in %USERPROFILE%\.dotnet\tools\:
-        dotnet tool install -g BepInEx.AssemblyPublicizer.Cli
-  -->
-  <!--
-    The target is conditioned to run only when building the 'UXAssist' project (the
-    designated first-built project in this solution), OR when either game DLL is
-    missing entirely (e.g. after a manual deletion).  This ensures the target fires
-    exactly once per solution build even when projects are built in parallel (-m),
-    while still recovering automatically if the DLLs are absent.
-
-    The PowerShell script additionally acquires an exclusive file lock on
-    AssemblyFromGame/.update.lock so that the rare case where the !Exists fallback
-    triggers multiple projects concurrently is also handled safely.
-  -->
-  <Target Name="UpdateGameDlls" BeforeTargets="BeforeBuild"
-          Condition="'$(MSBuildProjectName)' == 'UXAssist'
-                     Or !Exists('$(MSBuildThisFileDirectory)AssemblyFromGame\Assembly-CSharp.dll')
-                     Or !Exists('$(MSBuildThisFileDirectory)AssemblyFromGame\UnityEngine.UI.dll')"
-          >
-    <Exec
-      Command="powershell.exe -NoProfile -ExecutionPolicy Bypass -File &quot;$(MSBuildThisFileDirectory)UpdateGameDlls.ps1&quot; -ProjectRoot &quot;$(MSBuildThisFileDirectory.TrimEnd('\\/'))&quot;"
-      ConsoleToMSBuild="true"
-      IgnoreExitCode="false"
-      WorkingDirectory="$(MSBuildThisFileDirectory)" />
-  </Target>
 
   <!--
     ZipMod target: assembles a Thunderstore-ready zip under package/.

UpdateGameDlls.ps1

@@ -130,34 +130,7 @@ if (-not $publicizer) {
 }
 
 # ---------------------------------------------------------------------------
-# 5. Acquire an exclusive file lock so that concurrent MSBuild nodes (triggered
-#    by the !Exists fallback condition) cannot write the DLLs simultaneously.
-#    The lock is released automatically in the finally block.
-# ---------------------------------------------------------------------------
-$lockPath   = Join-Path $OUTPUT_DIR '.update.lock'
-$lockStream = $null
-try {
-    # Retry loop: wait up to 60 s for the lock (another node may be updating)
-    $deadline = [DateTime]::UtcNow.AddSeconds(60)
-    while ($true) {
-        try {
-            $lockStream = [System.IO.File]::Open(
-                $lockPath,
-                [System.IO.FileMode]::OpenOrCreate,
-                [System.IO.FileAccess]::ReadWrite,
-                [System.IO.FileShare]::None)
-            break   # lock acquired
-        } catch [System.IO.IOException] {
-            if ([DateTime]::UtcNow -ge $deadline) {
-                Write-Warning 'UpdateGameDlls: Timed out waiting for lock; skipping DLL update.'
-                exit 0
-            }
-            Start-Sleep -Milliseconds 200
-        }
-    }
-
-# ---------------------------------------------------------------------------
-# 6. For each DLL: compare timestamps, publicize if game copy is newer
+# 5. For each DLL: compare timestamps, publicize if game copy is newer
 # ---------------------------------------------------------------------------
 $updated = 0
 foreach ($dll in $DSP_DLLS) {
@@ -203,8 +176,3 @@ if ($updated -gt 0) {
 } else {
     Write-Host 'UpdateGameDlls: All DLLs are up-to-date.'
 }
-
-} finally {
-    # Release the exclusive lock regardless of success or failure
-    if ($lockStream) { $lockStream.Close() }
-}