Fix all ESLint errors: remove unused imports, replace any types

- Remove ~60 unused imports and variables across 88 files
- Replace ~80 `any` type annotations with proper types (unknown,
  Record<string, unknown>, or specific types)
- Prefix unused callback args with underscore
- Fix unescaped JSX entities
- Lint now passes cleanly (0 errors, 2 intentional img warnings)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/invoices/invoice-detail.tsx

@@ -2,7 +2,7 @@
 
 import { useState } from 'react';
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
-import { format } from 'date-fns';
+
 import { Loader2, Send, CreditCard } from 'lucide-react';
 import { useForm } from 'react-hook-form';
 import { zodResolver } from '@hookform/resolvers/zod';
@@ -33,7 +33,7 @@ export function InvoiceDetail({ invoiceId }: InvoiceDetailProps) {
   const queryClient = useQueryClient();
   const [tab, setTab] = useState('overview');
 
-  const { data, isLoading, error } = useQuery<{ data: any }>({
+  const { data, isLoading, error } = useQuery<{ data: Record<string, unknown> }>({
     queryKey: ['invoices', invoiceId],
     queryFn: () => apiFetch(`/api/v1/invoices/${invoiceId}`),
   });
@@ -172,7 +172,7 @@ export function InvoiceDetail({ invoiceId }: InvoiceDetailProps) {
                     <span className="col-span-2 text-right">Unit Price</span>
                     <span className="col-span-2 text-right">Total</span>
                   </div>
-                  {invoice.lineItems.map((li: any) => (
+                  {(invoice.lineItems as Record<string, unknown>[]).map((li) => (
                     <div key={li.id} className="grid grid-cols-12 gap-2 text-sm">
                       <span className="col-span-6">{li.description}</span>
                       <span className="col-span-2 text-right tabular-nums">{li.quantity}</span>
@@ -239,7 +239,7 @@ export function InvoiceDetail({ invoiceId }: InvoiceDetailProps) {
         <TabsContent value="expenses" className="pt-4">
           {invoice.linkedExpenses && invoice.linkedExpenses.length > 0 ? (
             <div className="space-y-2">
-              {invoice.linkedExpenses.map((exp: any) => (
+              {(invoice.linkedExpenses as Record<string, unknown>[]).map((exp) => (
                 <div
                   key={exp.id}
                   className="flex items-center justify-between p-3 border rounded-md text-sm"