[windows] Add NSIS installer (#4008)

Adds an NSIS Windows installer file. Includes:

- Installation to `user\AppData\Local\Eden` (user install; does not require administrator and makes the integrated updater work and same as e.g. yuzu, Citra, Azahar)
- Shortcuts for Start Menu and optionally to Desktop
- File association with `.nsp`, `.xci`, `.nro` and `.kip`
- Throughout uninstallation and registry cleanup

And finally, needs to be implemented into the GitHub CI workflow, will submit a PR there later uwu

Co-authored-by: RedBlackAka <140876408+RedBlackAka@users.noreply.github.com>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4008
Reviewed-by: crueter <crueter@eden-emu.dev>
Reviewed-by: Lizzie <lizzie@eden-emu.dev>

dist/installer.nsi

@@ -0,0 +1,184 @@
+; SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+; SPDX-License-Identifier: GPL-3.0-or-later
+
+; Usage:
+;   get the latest nsis: https://nsis.sourceforge.io/Download
+
+; Require these for makensis.
+!ifndef PRODUCT_VERSION
+  !error "PRODUCT_VERSION must be defined"
+!endif
+
+!ifndef ARCH
+  !error "ARCH must be defined"
+!endif
+
+!ifndef VARIANT
+  !error "VARIANT must be defined"
+!endif
+
+Unicode true
+ManifestDPIAware true
+
+!define PRODUCT_NAME "Eden"
+!define PRODUCT_PUBLISHER "Utopia LLC"
+!define PRODUCT_WEB_SITE "https://git.eden-emu.dev"
+!define PRODUCT_DIR_REGKEY "Software\Microsoft\Windows\CurrentVersion\App Paths\${PRODUCT_NAME}.exe"
+!define PRODUCT_UNINST_KEY "Software\Microsoft\Windows\CurrentVersion\Uninstall\${PRODUCT_NAME}"
+
+!define BINARY_SOURCE_DIR "..\bin"
+
+Name "${PRODUCT_NAME}"
+OutFile "${PRODUCT_NAME}-Windows-${PRODUCT_VERSION}-${ARCH}-${VARIANT}-installer.exe"
+SetCompressor /SOLID lzma
+InstallDir "$LOCALAPPDATA\$(^Name)" 
+ShowInstDetails show
+ShowUnInstDetails show
+
+!include "MUI2.nsh"
+; Custom page plugin
+!include "nsDialogs.nsh"
+
+; MUI Settings
+!define MUI_ICON "eden.ico"
+!define MUI_UNICON "${NSISDIR}\Contrib\Graphics\Icons\modern-uninstall.ico"
+
+; License page
+!insertmacro MUI_PAGE_LICENSE "..\LICENSE.txt"
+; Desktop Shortcut page
+Page custom desktopShortcutPageCreate desktopShortcutPageLeave
+; Directory page
+!insertmacro MUI_PAGE_DIRECTORY
+; Instfiles page
+!insertmacro MUI_PAGE_INSTFILES
+; Finish page
+!define MUI_FINISHPAGE_RUN "$INSTDIR\eden.exe"
+!insertmacro MUI_PAGE_FINISH
+
+; Uninstaller pages
+!insertmacro MUI_UNPAGE_INSTFILES
+
+; Variables
+Var DesktopShortcutPageDialog
+Var DesktopShortcutCheckbox
+Var DesktopShortcut
+
+; Language files
+!insertmacro MUI_LANGUAGE "English"
+!insertmacro MUI_LANGUAGE "SimpChinese"
+!insertmacro MUI_LANGUAGE "TradChinese"
+!insertmacro MUI_LANGUAGE "Danish"
+!insertmacro MUI_LANGUAGE "Dutch"
+!insertmacro MUI_LANGUAGE "French"
+!insertmacro MUI_LANGUAGE "German"
+!insertmacro MUI_LANGUAGE "Hungarian"
+!insertmacro MUI_LANGUAGE "Italian"
+!insertmacro MUI_LANGUAGE "Japanese"
+!insertmacro MUI_LANGUAGE "Korean"
+!insertmacro MUI_LANGUAGE "Lithuanian"
+!insertmacro MUI_LANGUAGE "Norwegian"
+!insertmacro MUI_LANGUAGE "Polish"
+!insertmacro MUI_LANGUAGE "PortugueseBR"
+!insertmacro MUI_LANGUAGE "Romanian"
+!insertmacro MUI_LANGUAGE "Russian"
+!insertmacro MUI_LANGUAGE "Spanish"
+!insertmacro MUI_LANGUAGE "Swedish"
+!insertmacro MUI_LANGUAGE "Turkish"
+!insertmacro MUI_LANGUAGE "Vietnamese"
+
+; MUI end ------
+
+Function .onInit
+  StrCpy $DesktopShortcut 1
+
+  !insertmacro MUI_LANGDLL_DISPLAY
+FunctionEnd
+
+Function desktopShortcutPageCreate
+  !insertmacro MUI_HEADER_TEXT "Create Desktop Shortcut" "Would you like to create a desktop shortcut?"
+  nsDialogs::Create 1018
+  Pop $DesktopShortcutPageDialog
+  ${If} $DesktopShortcutPageDialog == error
+    Abort
+  ${EndIf}
+
+  ${NSD_CreateCheckbox} 0u 0u 100% 12u "Create a desktop shortcut"
+  Pop $DesktopShortcutCheckbox
+  ${NSD_SetState} $DesktopShortcutCheckbox $DesktopShortcut
+
+  nsDialogs::Show
+FunctionEnd
+
+Function desktopShortcutPageLeave
+  ${NSD_GetState} $DesktopShortcutCheckbox $DesktopShortcut
+FunctionEnd
+
+Section "Base"
+  ExecWait '"$INSTDIR\uninst.exe" /S _?=$INSTDIR'
+
+  SectionIn RO
+
+  SetOutPath "$INSTDIR"
+
+  ; The binplaced build output will be included verbatim.
+  File /r "${BINARY_SOURCE_DIR}\*"
+
+  ; Create start menu and desktop shortcuts
+  CreateShortCut "$SMPROGRAMS\$(^Name).lnk" "$INSTDIR\eden.exe"
+  ${If} $DesktopShortcut == 1
+    CreateShortCut "$DESKTOP\$(^Name).lnk" "$INSTDIR\eden.exe"
+  ${EndIf}
+SectionEnd
+
+!include "FileFunc.nsh"
+
+Section -Post
+  WriteUninstaller "$INSTDIR\uninst.exe"
+
+  WriteRegStr HKCU "${PRODUCT_DIR_REGKEY}" "" "$INSTDIR\eden.exe"
+
+  ; Write metadata for add/remove programs applet
+  WriteRegStr HKCU "${PRODUCT_UNINST_KEY}" "DisplayName" "$(^Name)"
+  WriteRegStr HKCU "${PRODUCT_UNINST_KEY}" "UninstallString" "$INSTDIR\uninst.exe"
+  WriteRegStr HKCU "${PRODUCT_UNINST_KEY}" "DisplayIcon" "$INSTDIR\eden.exe"
+  WriteRegStr HKCU "${PRODUCT_UNINST_KEY}" "URLInfoAbout" "${PRODUCT_WEB_SITE}"
+  WriteRegStr HKCU "${PRODUCT_UNINST_KEY}" "Publisher" "${PRODUCT_PUBLISHER}"
+  WriteRegStr HKCU "${PRODUCT_UNINST_KEY}" "InstallLocation" "$INSTDIR"
+  ${GetSize} "$INSTDIR" "/S=0K" $0 $1 $2
+  IntFmt $0 "0x%08X" $0
+  WriteRegDWORD HKCU "${PRODUCT_UNINST_KEY}" "EstimatedSize" "$0"
+
+  WriteRegStr HKCU "Software\Classes\.nsp" "" "$(^Name)"
+  WriteRegStr HKCU "Software\Classes\.xci" "" "$(^Name)"
+  WriteRegStr HKCU "Software\Classes\.nro" "" "$(^Name)"
+  WriteRegStr HKCU "Software\Classes\.kip" "" "$(^Name)"
+  WriteRegStr HKCU "Software\Classes\$(^Name)\DefaultIcon" "" "$INSTDIR\eden.exe,0"
+  WriteRegStr HKCU "Software\Classes\$(^Name)\Shell\open\command" "" '"$INSTDIR\eden.exe" %1'
+SectionEnd
+
+Section Uninstall
+  Delete "$DESKTOP\$(^Name).lnk"
+  Delete "$SMPROGRAMS\$(^Name).lnk"
+
+  ; Be a bit careful to not delete files a user may have put into the install directory.
+  Delete "$INSTDIR\eden.exe"
+  Delete "$INSTDIR\eden-cli.exe"
+  Delete "$INSTDIR\uninst.exe"
+  Delete "$INSTDIR\LICENSE.txt"
+  Delete "$INSTDIR\README.md"
+  RMDir /r "$INSTDIR\LICENSES"
+  RMDir "$INSTDIR"
+
+  DeleteRegKey HKCU "Software\Classes\.nsp"
+  DeleteRegKey HKCU "Software\Classes\.xci"
+  DeleteRegKey HKCU "Software\Classes\.nro"
+  DeleteRegKey HKCU "Software\Classes\.kip"
+  DeleteRegKey HKCU "Software\Classes\$(^Name)"
+
+  DeleteRegKey HKCU "Software\Classes\discord-1397286652128264252"
+
+  DeleteRegKey HKCU "${PRODUCT_UNINST_KEY}"
+  DeleteRegKey HKCU "${PRODUCT_DIR_REGKEY}"
+
+  SetAutoClose true
+SectionEnd