Add Microsoft Store MSIX package build (#14142)

* docs: add MSIX Store build design spec

* docs: update MSIX spec (PFN deep link, .drc, Associate tab) and add implementation plan

* ci: add MSIX logo asset generator and generated assets

* ci: fix MSIX asset rendering edge bleed (PixelOffsetMode) and make output order deterministic

* ci: add MSIX AppxManifest template

* ci: add MSIX packaging script

* ci: make build_msix.ps1 stage-only exit dot-source safe

* ci: build MSIX Store package in Windows job

* ci: run MSIX pack after existing Windows uploads and keep it out of release downloads

* feat: add MSIX packaged-context detection helpers

* fix: resolve MSIX package APIs dynamically to keep Win7 loadable

* feat: suppress self-update in MSIX Store build

* feat: suppress runtime file associations in MSIX Store build

* feat: keep version check in MSIX build, point update dialog at the Store

The update check is notification-only (OrcaSlicer never auto-downloads),
so the Store build keeps checking for new versions instead of skipping
the check. What changes when packaged is the new-version dialog: the
Download button is hidden, the info text asks the user to update from
the Microsoft Store, and the hyperlink / wxID_YES action opens the Store
product page instead of the GitHub release page.

* docs: align spec verification plan with Store-redirect updater behavior

* feat: default MSIX identity to the reserved Partner Center values

* feat: render MSIX logos full-bleed from the gradient-circle SVG

* feat: point update dialog Download button at the Store in MSIX builds

* feat: link Associate tab to Windows Default Apps settings in MSIX builds

* docs: align spec with review-driven logo, dialog and Associate-tab changes

* clearn up

scripts/msix/AppxManifest.xml

@@ -0,0 +1,75 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Package
+  xmlns="http://schemas.microsoft.com/appx/manifest/foundation/windows10"
+  xmlns:uap="http://schemas.microsoft.com/appx/manifest/uap/windows10"
+  xmlns:rescap="http://schemas.microsoft.com/appx/manifest/foundation/windows10/restrictedcapabilities"
+  xmlns:rescap3="http://schemas.microsoft.com/appx/manifest/foundation/windows10/restrictedcapabilities/3"
+  xmlns:desktop6="http://schemas.microsoft.com/appx/manifest/desktop/windows10/6"
+  xmlns:virtualization="http://schemas.microsoft.com/appx/manifest/virtualization/windows10"
+  IgnorableNamespaces="uap rescap rescap3 desktop6 virtualization">
+
+  <Identity Name="@MSIX_IDENTITY_NAME@"
+            Publisher="@MSIX_PUBLISHER@"
+            Version="@MSIX_VERSION@"
+            ProcessorArchitecture="x64" />
+
+  <Properties>
+    <DisplayName>OrcaSlicer</DisplayName>
+    <PublisherDisplayName>@MSIX_PUBLISHER_DISPLAY_NAME@</PublisherDisplayName>
+    <Logo>Assets\StoreLogo.png</Logo>
+    <!-- Keep config in the real %APPDATA%\OrcaSlicer so it survives uninstall and
+         is shared with the classic (NSIS/portable) install.
+         Win10 1903+: coarse switch disables AppData write virtualization entirely.
+         Win11+: fine-grained exclusion below takes precedence over the coarse switch. -->
+    <desktop6:FileSystemWriteVirtualization>disabled</desktop6:FileSystemWriteVirtualization>
+    <virtualization:FileSystemWriteVirtualization>
+      <virtualization:ExcludedDirectories>
+        <virtualization:ExcludedDirectory>$(KnownFolder:RoamingAppData)\OrcaSlicer</virtualization:ExcludedDirectory>
+      </virtualization:ExcludedDirectories>
+    </virtualization:FileSystemWriteVirtualization>
+  </Properties>
+
+  <Dependencies>
+    <TargetDeviceFamily Name="Windows.Desktop" MinVersion="10.0.18362.0" MaxVersionTested="10.0.26100.0" />
+  </Dependencies>
+
+  <Resources>
+    <Resource Language="en-us" />
+  </Resources>
+
+  <Applications>
+    <Application Id="OrcaSlicer" Executable="orca-slicer.exe" EntryPoint="Windows.FullTrustApplication">
+      <uap:VisualElements
+        DisplayName="OrcaSlicer"
+        Description="Open-source slicer for FDM 3D printers"
+        BackgroundColor="transparent"
+        Square150x150Logo="Assets\Square150x150Logo.png"
+        Square44x44Logo="Assets\Square44x44Logo.png" />
+      <Extensions>
+        <uap:Extension Category="windows.fileTypeAssociation">
+          <uap:FileTypeAssociation Name="orcaslicer-models">
+            <uap:SupportedFileTypes>
+              <uap:FileType>.3mf</uap:FileType>
+              <uap:FileType>.stl</uap:FileType>
+              <uap:FileType>.step</uap:FileType>
+              <uap:FileType>.stp</uap:FileType>
+              <uap:FileType>.gcode</uap:FileType>
+              <uap:FileType>.drc</uap:FileType>
+            </uap:SupportedFileTypes>
+            <rescap3:MigrationProgIds>
+              <rescap3:MigrationProgId>Orca.Slicer.1</rescap3:MigrationProgId>
+            </rescap3:MigrationProgIds>
+          </uap:FileTypeAssociation>
+        </uap:Extension>
+        <uap:Extension Category="windows.protocol">
+          <uap:Protocol Name="orcaslicer" />
+        </uap:Extension>
+      </Extensions>
+    </Application>
+  </Applications>
+
+  <Capabilities>
+    <rescap:Capability Name="runFullTrust" />
+    <rescap:Capability Name="unvirtualizedResources" />
+  </Capabilities>
+</Package>