Register .qetz in the remaining packaging files

- register_filetypes.bat (portable Windows build, two copies): .qetz
  opens with QElectroTech like .qet.
- AppStream metadata: lists the four file types QElectroTech opens.
- macOS Info.plist: declares the .qet and .qetz types (UTIs), which
  recent macOS needs to associate an extension with the application.

Review of #1472 (scorpio810, point 3).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

build-aux/windows/nsis_base/files/register_filetypes.bat

@@ -69,6 +69,10 @@ set reg_file=qet_install_file_associations.reg
 	echo [HKEY_CURRENT_USER\Software\Classes\qet_diagram_file\shell\open\command]
 	echo @="\"%final_qet_exe%\" \"%%1\""
 	
+	rem *.qetz (zipped project): the same file type as *.qet
+	echo [HKEY_CURRENT_USER\Software\Classes\.qetz]
+	echo @="qet_diagram_file"
+	
 	rem association de fichier *.elmt
 	echo [HKEY_CURRENT_USER\Software\Classes\.elmt]
 	echo @="qet_element_file"

misc/Info.plist

@@ -34,10 +34,62 @@
 				<string>qet</string>
 				<string>qetz</string>
 			</array>
+			<key>LSItemContentTypes</key>
+			<array>
+				<string>org.qelectrotech.project</string>
+				<string>org.qelectrotech.project-zip</string>
+			</array>
+			<key>LSHandlerRank</key>
+			<string>Owner</string>
 			<key>CFBundleTypeRole</key>
 			<string>Editor</string>
 		</dict>
 	</array>
+	<key>UTExportedTypeDeclarations</key>
+	<array>
+		<dict>
+			<key>UTTypeIdentifier</key>
+			<string>org.qelectrotech.project</string>
+			<key>UTTypeDescription</key>
+			<string>QElectroTech project</string>
+			<key>UTTypeConformsTo</key>
+			<array>
+				<string>public.xml</string>
+			</array>
+			<key>UTTypeIconFile</key>
+			<string>qet</string>
+			<key>UTTypeTagSpecification</key>
+			<dict>
+				<key>public.filename-extension</key>
+				<array>
+					<string>qet</string>
+				</array>
+				<key>public.mime-type</key>
+				<string>application/x-qet-project</string>
+			</dict>
+		</dict>
+		<dict>
+			<key>UTTypeIdentifier</key>
+			<string>org.qelectrotech.project-zip</string>
+			<key>UTTypeDescription</key>
+			<string>QElectroTech zipped project</string>
+			<key>UTTypeConformsTo</key>
+			<array>
+				<string>public.zip-archive</string>
+			</array>
+			<key>UTTypeIconFile</key>
+			<string>qet</string>
+			<key>UTTypeTagSpecification</key>
+			<dict>
+				<key>public.filename-extension</key>
+				<array>
+					<string>qetz</string>
+				</array>
+				<key>public.mime-type</key>
+				<string>application/x-qet-project+zip</string>
+			</dict>
+		</dict>
+	</array>
 	<key>CFBundleExecutable</key>
 	<string>qelectrotech</string>
 	<key>CFBundleIconFile</key>

misc/qelectrotech.appdata.xml

@@ -37,6 +37,12 @@
  <summary xml:lang="tr">Elektrik şeması düzenleyici</summary>
  <summary xml:lang="uk">Редактор електричних схем</summary>
  <summary xml:lang="zh">电气图编辑器</summary>
+ <provides>
+  <mediatype>application/x-qet-project</mediatype>
+  <mediatype>application/x-qet-project+zip</mediatype>
+  <mediatype>application/x-qet-element</mediatype>
+  <mediatype>application/x-qet-titleblock</mediatype>
+ </provides>
  <content_rating type="oars-1.1"/>
  <releases>
      <release version="0.100.1-dev" date="2026"/>

misc/register_filetypes.bat

@@ -69,6 +69,10 @@ set reg_file=qet_install_file_associations.reg
 	echo [HKEY_CURRENT_USER\Software\Classes\qet_diagram_file\shell\open\command]
 	echo @="\"%final_qet_exe%\" \"%%1\""
 	
+	rem *.qetz (zipped project): the same file type as *.qet
+	echo [HKEY_CURRENT_USER\Software\Classes\.qetz]
+	echo @="qet_diagram_file"
+	
 	rem association de fichier *.elmt
 	echo [HKEY_CURRENT_USER\Software\Classes\.elmt]
 	echo @="qet_element_file"