Align store calls with selected-company scoping and add entity numbers.

Drop companyId from company-scoped store wrappers and routes, add GET /entity/next-number plus optional number on entity create/update, and document dashdbschema API.md lookup in sibling-repos.

src/api/routes/article.js

@@ -45,6 +45,7 @@ function parseFullHash(value) {
 }
 
 function articleErrorStatus(error) {
+    if (error.message === 'No company selected') return 400;
     if (error.message === 'Not authorized') return 403;
     if (error.message === 'Parent not found') return 404;
     if (error.message === 'Article not found') return 404;
@@ -230,7 +231,7 @@ export function register(app, basePath = '') {
         }
 
         try {
-            const rows = await db.listExport(req.user.id, companyId, categoryId);
+            const rows = await db.listExport(req.user.id, categoryId);
 
             const csv = buildArtikelCsv(rows);
 
@@ -1376,7 +1377,7 @@ export function register(app, basePath = '') {
         }
 
         try {
-            const articles = await db.listSearchIndex(req.user.id, companyId);
+            const articles = await db.listSearchIndex(req.user.id);
             res.status(200).json({ articles });
         } catch (error) {
             const status = articleErrorStatus(error);