feat(all-leads): remove stray Back button + wire Export CSV

- drop the header Back button (cosmetic; useNavigate + ArrowLeft icon
  removed with it)
- Export CSV now downloads the currently-filtered list — respects tab,
  search, campaign filter and active sort order. Headers: Phone /
  First/Last Name / Email / Source / Status / Campaign / Assigned
  Agent / First Contact / Last Contact / Created / Age (days).
- csv-utils: rowsToCsv + downloadCsv helpers. Values quoted, embedded
  quotes escaped, leading =/+/-/@ prefixed with a single quote to
  defeat CSV injection when opened in Excel. UTF-8 BOM on the blob
  so Excel recognises non-ASCII names/addresses.

src/lib/csv-utils.ts

@@ -1,5 +1,36 @@
 export type CSVRow = Record<string, string>;
 
+// CSV write-side. Quote every value and escape embedded quotes. Prefix
+// ="+-@ with a single quote so Excel doesn't interpret them as formulas
+// (classic CSV-injection vector on exports opened in spreadsheet apps).
+const escapeCsvCell = (raw: unknown): string => {
+    const value = raw == null ? '' : String(raw);
+    const sanitized = /^[=+\-@]/.test(value) ? `'${value}` : value;
+    return `"${sanitized.replace(/"/g, '""')}"`;
+};
+
+export const rowsToCsv = (headers: string[], rows: Array<Record<string, unknown>>): string => {
+    const lines = [headers.map(escapeCsvCell).join(',')];
+    for (const row of rows) {
+        lines.push(headers.map((h) => escapeCsvCell(row[h])).join(','));
+    }
+    return lines.join('\r\n');
+};
+
+export const downloadCsv = (filename: string, csv: string): void => {
+    // BOM prefix so Excel recognises UTF-8 for non-ASCII names/addresses.
+    const blob = new Blob(['\ufeff', csv], { type: 'text/csv;charset=utf-8' });
+    const url = URL.createObjectURL(blob);
+    const link = document.createElement('a');
+    link.href = url;
+    link.download = filename;
+    document.body.appendChild(link);
+    link.click();
+    document.body.removeChild(link);
+    URL.revokeObjectURL(url);
+};
+
+
 export type CSVParseResult = {
     headers: string[];
     rows: CSVRow[];

src/pages/all-leads.tsx

@@ -1,10 +1,9 @@
 import type { FC } from 'react';
 import { useMemo, useState } from 'react';
-import { useSearchParams, useNavigate } from 'react-router';
+import { useSearchParams } from 'react-router';
 import { FontAwesomeIcon } from '@fortawesome/react-fontawesome';
-import { faArrowLeft, faArrowDownToLine, faMagnifyingGlass } from '@fortawesome/pro-duotone-svg-icons';
+import { faArrowDownToLine, faMagnifyingGlass } from '@fortawesome/pro-duotone-svg-icons';
 
-const ArrowLeft: FC<{ className?: string }> = ({ className }) => <FontAwesomeIcon icon={faArrowLeft} className={className} />;
 const Download01: FC<{ className?: string }> = ({ className }) => <FontAwesomeIcon icon={faArrowDownToLine} className={className} />;
 const SearchLg: FC<{ className?: string }> = ({ className }) => <FontAwesomeIcon icon={faMagnifyingGlass} className={className} />;
 import { Button } from '@/components/base/buttons/button';
@@ -24,6 +23,8 @@ import { useLeads } from '@/hooks/use-leads';
 import { useAuth } from '@/providers/auth-provider';
 import { useData } from '@/providers/data-provider';
 import { cx } from '@/utils/cx';
+import { rowsToCsv, downloadCsv } from '@/lib/csv-utils';
+import { notify } from '@/lib/toast';
 import type { Lead, LeadSource, LeadStatus } from '@/types/entities';
 
 type TabKey = 'new' | 'my-leads' | 'all';
@@ -38,7 +39,6 @@ const PAGE_SIZE = 15;
 
 export const AllLeadsPage = () => {
     const { user } = useAuth();
-    const navigate = useNavigate();
     const [searchParams] = useSearchParams();
     const initialSource = searchParams.get('source') as LeadSource | null;
     const [tab, setTab] = useState<TabKey>('new');
@@ -166,6 +166,44 @@ export const AllLeadsPage = () => {
         setSelectedIds([]);
     };
 
+    const handleExportCsv = () => {
+        // Export exactly what the user currently sees — same filters, same
+        // sort, same tab/campaign scope. Ignores pagination so the file
+        // contains every matching row, not just the current page.
+        if (displayLeads.length === 0) {
+            notify.error('Export CSV', 'No leads to export');
+            return;
+        }
+        const headers = [
+            'Phone', 'First Name', 'Last Name', 'Email',
+            'Source', 'Status', 'Campaign', 'Assigned Agent',
+            'First Contact', 'Last Contact', 'Created', 'Age (days)',
+        ];
+        const campaignNameById = new Map(campaigns.map((c) => [c.id, c.campaignName]));
+        const now = Date.now();
+        const rows = displayLeads.map((l) => {
+            const createdMs = l.createdAt ? new Date(l.createdAt).getTime() : null;
+            return {
+                'Phone': l.contactPhone?.[0]?.number ?? '',
+                'First Name': l.contactName?.firstName ?? '',
+                'Last Name': l.contactName?.lastName ?? '',
+                'Email': l.contactEmail?.[0]?.address ?? '',
+                'Source': l.leadSource ?? '',
+                'Status': l.leadStatus ?? '',
+                'Campaign': l.campaignId ? (campaignNameById.get(l.campaignId) ?? '') : '',
+                'Assigned Agent': l.assignedAgent ?? '',
+                'First Contact': l.firstContactedAt ?? '',
+                'Last Contact': l.lastContactedAt ?? '',
+                'Created': l.createdAt ?? '',
+                'Age (days)': createdMs ? String(Math.floor((now - createdMs) / 86400000)) : '',
+            };
+        });
+        const csv = rowsToCsv(headers, rows);
+        const today = new Date().toISOString().slice(0, 10);
+        downloadCsv(`leads-${tab}-${today}.csv`, csv);
+        notify.success('Export CSV', `${rows.length} lead${rows.length === 1 ? '' : 's'} exported`);
+    };
+
     const handlePageChange = (page: number) => {
         setCurrentPage(page);
         setSelectedIds([]);
@@ -231,14 +269,6 @@ export const AllLeadsPage = () => {
                 {/* Tabs + Controls row */}
                 <div className="flex shrink-0 items-center justify-between px-6 py-3 border-b border-secondary">
                     <div className="flex items-center gap-3">
-                        <Button
-                            onClick={() => navigate(-1)}
-                            color="secondary"
-                            size="sm"
-                            iconLeading={ArrowLeft}
-                            aria-label="Back"
-                        />
-
                         <Tabs selectedKey={tab} onSelectionChange={handleTabChange}>
                             <TabList items={tabItems} type="button-gray" size="sm">
                                 {(item) => (
@@ -267,6 +297,7 @@ export const AllLeadsPage = () => {
                             size="sm"
                             color="secondary"
                             iconLeading={Download01}
+                            onClick={handleExportCsv}
                         >
                             Export CSV
                         </Button>