Swedish: title blocks, installer, desktop/MIME files and man page

- Title block templates: Swedish labels for the multilingual fields
  (Datum, Titel, Fil, Blad, Upprättad av; ISO 7200 fields).
- Windows installer: translate the four AI assistant strings left in
  English, fix "Solvarme" and use "Symboler" for elements.
- Desktop, AppStream and MIME files: use the current terms (elscheman,
  symbol, ritningshuvud), add Swedish keywords and a .qetz comment.
- Add a Swedish man page.

Note: the Swedish texts in this commit were generated with an AI
assistant (Claude) and then reviewed by the Swedish translator.

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

titleblocks/default.titleblock

@@ -23,6 +23,7 @@
                 <translation lang="pt_BR">Autor</translation>
                 <translation lang="ro">Autor</translation>
                 <translation lang="ru">Автор</translation>
+                <translation lang="sv">Upprättad av</translation>
                 <translation lang="zh">作者</translation>
             </label>
         </field>
@@ -46,6 +47,7 @@
                 <translation lang="pt_BR">Título</translation>
                 <translation lang="ro">Titlu</translation>
                 <translation lang="ru">Название</translation>
+                <translation lang="sv">Titel</translation>
                 <translation lang="zh">职称</translation>
             </label>
         </field>
@@ -70,6 +72,7 @@
                 <translation lang="pt_BR">Arquivo</translation>
                 <translation lang="ro">Fisier</translation>
                 <translation lang="ru">Файл</translation>
+                <translation lang="sv">Fil</translation>
                 <translation lang="zh">文件名</translation>
             </label>
         </field>
@@ -94,6 +97,7 @@
                 <translation lang="pt_BR">Data</translation>
                 <translation lang="ro">Data</translation>
                 <translation lang="ru">Дата</translation>
+                <translation lang="sv">Datum</translation>
                 <translation lang="zh">日期</translation>
             </label>
         </field>
@@ -118,6 +122,7 @@
                 <translation lang="pt_BR">Folha</translation>
                 <translation lang="ro">Pagina</translation>
                 <translation lang="ru">Фолио</translation>
+                <translation lang="sv">Blad</translation>
                 <translation lang="zh">当前页</translation>
             </label>
         </field>