fix: invoice integrity — atomic numbering, safe delete, single create path

- Invoice numbers now come from DB function next_invoice_number()
  (max+1 per year under advisory lock) with a unique index; the old
  row-count method reused numbers after deletes and raced concurrent
  creates, which broke public pay links
- Remove dead standalone TeamCreateInvoice page; the TeamInvoices
  modal is the single create path (page had already drifted)
- Invoice delete now asks for confirmation and only un-bills tasks/
  submissions not billed on another invoice
- Created invoice shows correct "sent" status in list without reload
- Invoice/due dates computed at save time, not module load
- Reopening a paid invoice clears stale stripe_fee
- Stripe webhook markPaid is idempotent (no double receipts)
- subcontractor_invoice_items.version_number column stores billing
  version explicitly; description parsing kept as legacy fallback
- Drop unused buildInvoiceStatusByKey/deriveVersionStatus

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/App.jsx

@@ -44,7 +44,6 @@ const CompaniesPage = lazy(() => import('./pages/Companies'));
 const CompanyDetail = lazy(() => import('./pages/CompanyDetail'));
 const TeamInvoices = lazy(() => import('./pages/team/TeamInvoices'));
 const TaskDetail = lazy(() => import('./pages/TaskDetail'));
-const TeamCreateInvoice = lazy(() => import('./pages/team/TeamCreateInvoice'));
 const TeamCreateSubcontractorPO = lazy(() => import('./pages/team/TeamCreateSubcontractorPO'));
 const TeamInvoiceDetail = lazy(() => import('./pages/team/TeamInvoiceDetail'));
 const TeamSubcontractorPODetail = lazy(() => import('./pages/team/TeamSubcontractorPODetail'));
@@ -111,13 +110,13 @@ export default function App() {
           <Route path="/requests" element={<Navigate to="/tasks" replace />} />
           <Route path="/team-projects" element={<Navigate to="/tasks" replace />} />
           <Route path="/finances" element={<ProtectedRoute role="team"><TeamInvoices /></ProtectedRoute>} />
-          <Route path="/finances/new" element={<ProtectedRoute role="team"><TeamCreateInvoice /></ProtectedRoute>} />
+          <Route path="/finances/new" element={<Navigate to="/finances" replace />} />
           <Route path="/subcontractor-pos/new" element={<ProtectedRoute role="team"><TeamCreateSubcontractorPO /></ProtectedRoute>} />
           <Route path="/finances/:id" element={<ProtectedRoute role="team"><TeamInvoiceDetail /></ProtectedRoute>} />
           <Route path="/subcontractor-pos/:id" element={<ProtectedRoute role="team"><TeamSubcontractorPODetail /></ProtectedRoute>} />
           <Route path="/sub-invoices/:id" element={<ProtectedRoute role="team"><TeamSubInvoiceDetail /></ProtectedRoute>} />
           <Route path="/invoices" element={<Navigate to="/finances" replace />} />
-          <Route path="/invoices/new" element={<Navigate to="/finances/new" replace />} />
+          <Route path="/invoices/new" element={<Navigate to="/finances" replace />} />
           <Route path="/invoices/:id" element={<RedirectTeamInvoiceDetail />} />
           <Route path="/survey-maker" element={<ProtectedRoute role={['team', 'external']}><SurveyMaker /></ProtectedRoute>} />
           <Route path="/brand-book" element={<ProtectedRoute role={['team', 'external']}><BrandBook /></ProtectedRoute>} />