fix: show membership date for stores without pickups

Treat Foodsharing's zero lastFetch value as no pickup, store memberSince, and
show compact, visible mobile status information without hover tooltips.

services/lastPickupInfo.js

@@ -25,16 +25,23 @@ function getStaleLastPickupStoreIds(config = [], now = Date.now()) {
 
 function parseLastFetchTimestamp(value) {
   if (typeof value === 'string') {
-    return parseTimestamp(value);
+    if (value.trim() !== '' && Number.isFinite(Number(value))) {
+      return parseLastFetchTimestamp(Number(value));
+    }
+    const timestamp = parseTimestamp(value);
+    return timestamp && timestamp > 0 ? timestamp : null;
   }
   if (!Number.isFinite(Number(value))) {
     return null;
   }
   const numericValue = Number(value);
+  if (numericValue <= 0) {
+    return null;
+  }
   return numericValue > 1e12 ? numericValue : numericValue * 1000;
 }
 
-function updateLastPickupInfo(entry, lastFetchValue, checkedAt = new Date()) {
+function updateLastPickupInfo(entry, lastFetchValue, memberSinceValue, checkedAt = new Date()) {
   if (!entry || typeof entry !== 'object') {
     return false;
   }
@@ -51,6 +58,17 @@ function updateLastPickupInfo(entry, lastFetchValue, checkedAt = new Date()) {
       entry.lastPickupAt = lastPickupAt;
       changed = true;
     }
+  } else if (entry.lastPickupAt) {
+    delete entry.lastPickupAt;
+    changed = true;
+  }
+  const memberSinceTimestamp = parseTimestamp(memberSinceValue);
+  if (memberSinceTimestamp !== null && memberSinceTimestamp > 0) {
+    const memberSinceAt = new Date(memberSinceTimestamp).toISOString();
+    if (entry.memberSinceAt !== memberSinceAt) {
+      entry.memberSinceAt = memberSinceAt;
+      changed = true;
+    }
   }
   return changed;
 }