Fix TypeScript compile errors blocking Docker build

- Add vite-env.d.ts for import.meta.env type support
- Remove unused imports: ChevronRight, useCallback (x2), today
- Silence unused attachments state read (keep setter for future use)
- Fix FloatManagement changeTinTargets reducer: drop unused k, fix v type

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

frontend/src/pages/MultiDayReport.tsx

@@ -1,7 +1,7 @@
 import { useState } from 'react'
 import { api } from '../api'
 import { PageHeader, Card, Btn } from '../components/Layout'
-import { fmtGBP, today } from '../types'
+import { fmtGBP } from '../types'
 
 interface SalesCol { gl_code: string; category: string; net_amount: number; vat_amount: number; gross_amount: number }
 interface ReconRow { category: string; banked_amount: number; reported_amount: number }