fix: retry transient pickup checks

Retry transient Foodsharing network failures such as socket hang up for safe read/check actions and add explicit pickup fallback scheduling, tick, and result logs so missed fallback checks can be diagnosed.

services/sessionRefresh.js

@@ -3,8 +3,14 @@ const sessionStore = require('./sessionStore');
 const notificationService = require('./notificationService');
 
 const ADMIN_SESSION_ERROR_COOLDOWN_MS = 6 * 60 * 60 * 1000;
+const DEFAULT_TRANSIENT_RETRY_DELAYS_MS = [1000, 3000];
+const NON_RETRIABLE_TRANSIENT_LABELS = new Set(['bookSlot']);
 const adminSessionErrorCooldowns = new Map();
 
+function wait(ms) {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
 function shouldNotifyAdminSessionError(key) {
   if (!key) {
     return false;
@@ -51,6 +57,26 @@ function isCsrfError(error) {
   return message.toLowerCase().includes('csrf');
 }
 
+function isTransientNetworkError(error) {
+  if (!error) {
+    return false;
+  }
+  if (error.response) {
+    return false;
+  }
+  const code = String(error.code || '').toUpperCase();
+  if (['ECONNRESET', 'ECONNABORTED', 'ETIMEDOUT', 'EPIPE', 'ENOTFOUND', 'EAI_AGAIN'].includes(code)) {
+    return true;
+  }
+  const message = String(error.message || '').toLowerCase();
+  return (
+    message.includes('socket hang up') ||
+    message.includes('timeout') ||
+    message.includes('network error') ||
+    message.includes('connection reset')
+  );
+}
+
 async function refreshSession(session, { label } = {}) {
   if (!session?.credentials?.email || !session?.credentials?.password) {
     console.warn(
@@ -110,7 +136,7 @@ async function ensureSession(session) {
   return true;
 }
 
-async function withSessionRetry(session, action, { label } = {}) {
+async function withSessionRetry(session, action, { label, transientRetries } = {}) {
   if (!session) {
     throw new Error('Session fehlt');
   }
@@ -120,22 +146,42 @@ async function withSessionRetry(session, action, { label } = {}) {
       throw new Error('Session konnte nicht erneuert werden');
     }
   }
-  try {
-    return await action();
-  } catch (error) {
-    if (!isUnauthorizedError(error) && !isCsrfError(error)) {
-      throw error;
+  const retryDelays = NON_RETRIABLE_TRANSIENT_LABELS.has(label)
+    ? []
+    : DEFAULT_TRANSIENT_RETRY_DELAYS_MS.slice(
+        0,
+        Number.isFinite(transientRetries) ? Math.max(0, transientRetries) : DEFAULT_TRANSIENT_RETRY_DELAYS_MS.length
+      );
+  let transientAttempt = 0;
+  while (true) {
+    try {
+      return await action();
+    } catch (error) {
+      if (isTransientNetworkError(error) && transientAttempt < retryDelays.length) {
+        transientAttempt += 1;
+        const delay = retryDelays[transientAttempt - 1];
+        console.warn(
+          `[SESSION] Transienter Fehler${label ? ` (${label})` : ''}: ${error.message}. ` +
+            `Retry ${transientAttempt}/${retryDelays.length} in ${delay}ms.`
+        );
+        await wait(delay);
+        continue;
+      }
+      if (!isUnauthorizedError(error) && !isCsrfError(error)) {
+        throw error;
+      }
+      const refreshed = await refreshSession(session, { label });
+      if (!refreshed) {
+        throw error;
+      }
+      return action();
     }
-    const refreshed = await refreshSession(session, { label });
-    if (!refreshed) {
-      throw error;
-    }
-    return action();
   }
 }
 
 module.exports = {
   ensureSession,
+  isTransientNetworkError,
   refreshSession,
   withSessionRetry
 };