Remove MigrationCleanup scheduled task entirely

With force-unmount + synchronous DelTree, the deferred cleanup task is
unnecessary. If DelTree can't delete some files (rare — process has a
handle open), the leftover files are inert: no service, no PATH entry,
no mounts reference them. Not worth the complexity of a SYSTEM-context
scheduled task.

Removes:
- gvfs-migration-cleanup.ps1 (script source)
- gvfs-migration-cleanup-task.xml.template (task XML template)
- BuildCleanupTaskXml MSBuild target + CleanupScriptsDir property
- CleanupTaskXml [Files] entry and /D define in ISCC invocation
- Fallback task registration in MigrateLegacyInstall()

Assisted-by: Claude Opus 4.6
Signed-off-by: Tyrie Vella <tyrielv@gmail.com>

Author: tyrielv

GVFS/GVFS.Installers/GVFS.Installers.csproj

@@ -5,8 +5,6 @@
     <LayoutPath>$(RepoOutPath)GVFS.Payload\bin\$(Configuration)\win-x64\</LayoutPath>
     <ProjFSAttachScriptsDir>$(MSBuildThisFileDirectory)..\..\scripts\projfs-attach\</ProjFSAttachScriptsDir>
     <ProjFSTaskXmlPath>$(IntermediateOutputPath)enable-projfs-on-all-drives-task.xml</ProjFSTaskXmlPath>
-    <CleanupScriptsDir>$(MSBuildThisFileDirectory)..\..\scripts\cleanup\</CleanupScriptsDir>
-    <CleanupTaskXmlPath>$(IntermediateOutputPath)gvfs-migration-cleanup-task.xml</CleanupTaskXmlPath>
   </PropertyGroup>
 
   <ItemDefinitionGroup>
@@ -32,12 +30,8 @@
     <Exec Command='powershell.exe -NoProfile -ExecutionPolicy Bypass -File "$(ProjFSAttachScriptsDir)build-task-xml.ps1" -ScriptPath "$(ProjFSAttachScriptsDir)enable-projfs-on-all-drives.ps1" -TemplatePath "$(ProjFSAttachScriptsDir)enable-projfs-on-all-drives-task.xml.template" -OutputPath "$(ProjFSTaskXmlPath)"' />
   </Target>
 
-  <Target Name="BuildCleanupTaskXml" BeforeTargets="CreateInstaller" Condition="'$(SkipCreateInstaller)' != 'true'">
-    <Exec Command='powershell.exe -NoProfile -ExecutionPolicy Bypass -File "$(ProjFSAttachScriptsDir)build-task-xml.ps1" -ScriptPath "$(CleanupScriptsDir)gvfs-migration-cleanup.ps1" -TemplatePath "$(CleanupScriptsDir)gvfs-migration-cleanup-task.xml.template" -OutputPath "$(CleanupTaskXmlPath)"' />
-  </Target>
-
   <Target Name="CreateInstaller" BeforeTargets="Build" Condition="'$(SkipCreateInstaller)' != 'true'">
-    <Exec Command='"$(PkgTools_InnoSetup)\tools\ISCC.exe" /DLayoutDir="$(LayoutPath)" /DGVFSVersion=$(GVFSVersion) /DProjFSTaskXml="$(ProjFSTaskXmlPath)" /DCleanupTaskXml="$(CleanupTaskXmlPath)" Setup.iss /O"$(OutputPath)"' />
+    <Exec Command='"$(PkgTools_InnoSetup)\tools\ISCC.exe" /DLayoutDir="$(LayoutPath)" /DGVFSVersion=$(GVFSVersion) /DProjFSTaskXml="$(ProjFSTaskXmlPath)" Setup.iss /O"$(OutputPath)"' />
   </Target>
 
   <Target Name="CleanInstaller" BeforeTargets="AfterClean">

GVFS/GVFS.Installers/Setup.iss

@@ -81,9 +81,6 @@ DestDir: "{localappdata}\GVFS\Versions\{#GVFSVersion}"; Flags: ignoreversion rec
 #ifdef ProjFSTaskXml
 Source: "{#ProjFSTaskXml}"; Flags: dontcopy
 #endif
-#ifdef CleanupTaskXml
-Source: "{#CleanupTaskXml}"; Flags: dontcopy
-#endif
 
 [Dirs]
 Name: "{app}\ProgramData\{#ServiceName}"; Permissions: users-readexec; Check: IsSystemModeInstall
@@ -1308,21 +1305,11 @@ begin
 
   // 6. Delete the legacy install directory synchronously.
   //    Since we force-unmounted all repos above, no mount processes
-  //    should be holding files open. If deletion fails for some files,
-  //    register the cleanup task as a fallback.
+  //    should be holding files open. Any leftover files are inert
+  //    (no service, no PATH, no mounts) — just wasted disk space.
   Log('MigrateLegacyInstall: Deleting legacy install directory ' + LegacyDir);
   if not DelTree(LegacyDir, True, True, True) then
-    begin
-      Log('MigrateLegacyInstall: Warning - could not fully delete ' + LegacyDir + ', registering cleanup task as fallback');
-      ExtractTemporaryFile('gvfs-migration-cleanup-task.xml');
-      if not Exec(ExpandConstant('{sys}\schtasks.exe'), '/Create /TN "\GVFS\MigrationCleanup" /XML "' + ExpandConstant('{tmp}\gvfs-migration-cleanup-task.xml') + '" /F', '', SW_HIDE, ewWaitUntilTerminated, ResultCode) or (ResultCode <> 0) then
-        Log('MigrateLegacyInstall: Warning - could not register cleanup task (exit ' + IntToStr(ResultCode) + ')')
-      else
-        begin
-          Log('MigrateLegacyInstall: Cleanup task registered as fallback');
-          Exec(ExpandConstant('{sys}\schtasks.exe'), '/Run /TN "\GVFS\MigrationCleanup"', '', SW_HIDE, ewWaitUntilTerminated, ResultCode);
-        end;
-    end
+    Log('MigrateLegacyInstall: Warning - could not fully delete ' + LegacyDir + ' (leftover files are inert)')
   else
     Log('MigrateLegacyInstall: Legacy install directory deleted');