Persist uploaded order CSVs across app restarts

Uploaded CSVs previously lived only in memory; reloading the app reset the
order list to the embedded SEED_ORDERS_CSV. Now every upload is written to a
new IndexedDB store so inspectors keep their order list after closing/reopening
the PWA.

- db.js: bump DB_VERSION to 4, add object store `ordersCsv` (keyPath 'id'),
  saveOrdersCsv(csvText) and loadOrdersCsv().
- csvLoader.js: loadOrdersFromUpload returns { text, orders } so the handler
  can persist the raw text alongside the parsed result.
- main.js: init() prefers the stored CSV, falls back to SEED_ORDERS_CSV. The
  upload handler persists the CSV before re-rendering.

public/js/main.js

@@ -33,7 +33,9 @@
     document.getElementById('csvFileInput').addEventListener('change', async (e) => {
       const file = e.target.files[0];
       if (!file) return;
-      A.state.orders = await I.loadOrdersFromUpload(file);
+      const { text, orders } = await I.loadOrdersFromUpload(file);
+      await I.saveOrdersCsv(text);
+      A.state.orders = orders;
       A.renderOverviewScreen(openOrder);
       e.target.value = '';
     });
@@ -91,7 +93,8 @@
 
   async function init() {
     await I.openDB();
-    A.state.orders = D.parseCSV(I.SEED_ORDERS_CSV);
+    const stored = await I.loadOrdersCsv();
+    A.state.orders = D.parseCSV(stored ? stored.csv : I.SEED_ORDERS_CSV);
     A.state.orderStatuses = await I.loadAllOrderStatuses();
 
     wireOverviewToolbar();

src/Infrastructure/csvLoader.js

@@ -1,6 +1,6 @@
 (function (I, D) {
   I.loadOrdersFromUpload = async function (file) {
     const text = await file.text();
-    return D.parseCSV(text);
+    return { text, orders: D.parseCSV(text) };
   };
 })(window.App.Infrastructure, window.App.Domain);

src/Infrastructure/db.js

@@ -1,6 +1,6 @@
 (function (I) {
   const DB_NAME = 'DuimstokInspecties';
-  const DB_VERSION = 3;
+  const DB_VERSION = 4;
   let db = null;
 
   I.openDB = function () {
@@ -12,6 +12,8 @@
           d.createObjectStore('inspections', { keyPath: 'orderNr' });
         if (!d.objectStoreNames.contains('orderStatuses'))
           d.createObjectStore('orderStatuses', { keyPath: 'orderKey' });
+        if (!d.objectStoreNames.contains('ordersCsv'))
+          d.createObjectStore('ordersCsv', { keyPath: 'id' });
       };
       req.onsuccess = (e) => { db = e.target.result; resolve(db); };
       req.onerror = (e) => reject(e);
@@ -53,6 +55,26 @@
     });
   };
 
+  I.saveOrdersCsv = async function (csvText) {
+    const d = await ensureDb();
+    return new Promise((resolve, reject) => {
+      const tx = d.transaction('ordersCsv', 'readwrite');
+      tx.objectStore('ordersCsv').put({ id: 'current', csv: csvText, uploadedAt: new Date().toISOString() });
+      tx.oncomplete = resolve;
+      tx.onerror = reject;
+    });
+  };
+
+  I.loadOrdersCsv = async function () {
+    const d = await ensureDb();
+    return new Promise((resolve, reject) => {
+      const tx = d.transaction('ordersCsv', 'readonly');
+      const req = tx.objectStore('ordersCsv').get('current');
+      req.onsuccess = () => resolve(req.result || null);
+      req.onerror = reject;
+    });
+  };
+
   I.loadAllOrderStatuses = async function () {
     const d = await ensureDb();
     return new Promise((resolve, reject) => {