Add post-fetch date filter for precise email matching

Gmail API only filters by day granularity, so emails at the boundary
can slip through. Now each fetched email's actual timestamp is checked
against the exact requested range (startDate to endDate) and emails
outside the range are skipped.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/server/src/services/scanService.ts

@@ -209,7 +209,7 @@ async function runScan(jobId: string, scanRequest: ScanRequest, userId: string,
       const batch = newIds.slice(i, i + BATCH_SIZE);
 
       // Fetch emails with concurrency limit
-      const emails: EmailMessage[] = [];
+      const fetchedEmails: EmailMessage[] = [];
       for (let j = 0; j < batch.length; j += CONCURRENT_FETCH) {
         const chunk = batch.slice(j, j + CONCURRENT_FETCH);
         const results = await Promise.allSettled(
@@ -218,7 +218,7 @@ async function runScan(jobId: string, scanRequest: ScanRequest, userId: string,
 
         for (const result of results) {
           if (result.status === 'fulfilled') {
-            emails.push(result.value);
+            fetchedEmails.push(result.value);
           } else {
             jobState.progress.emailsErrored++;
             const errMsg = result.reason?.message || 'Fetch error';
@@ -237,6 +237,29 @@ async function runScan(jobId: string, scanRequest: ScanRequest, userId: string,
         }
       }
 
+      // Post-fetch date filter: Gmail only filters by day, so we enforce exact range here
+      const rangeStart = new Date(dateRange.startDate).getTime();
+      const rangeEnd = new Date(dateRange.endDate).getTime();
+      const emails: EmailMessage[] = [];
+
+      for (const email of fetchedEmails) {
+        const emailTime = new Date(email.date).getTime();
+        if (emailTime >= rangeStart && emailTime <= rangeEnd) {
+          emails.push(email);
+        } else {
+          jobState.progress.emailsSkipped++;
+          logger.info({ emailId: email.emailId, emailDate: email.date, rangeStart: dateRange.startDate, rangeEnd: dateRange.endDate }, 'Skipping email outside date range');
+
+          emitToUser(userId, 'scan:progress', {
+            jobId,
+            processed: jobState.progress.emailsProcessed,
+            total: newIds.length,
+            skipped: jobState.progress.emailsSkipped,
+            errored: jobState.progress.emailsErrored,
+          });
+        }
+      }
+
       // Phase 3: AI parsing with concurrency limit
       for (let j = 0; j < emails.length; j += CONCURRENT_PARSE) {
         const parseChunk = emails.slice(j, j + CONCURRENT_PARSE);