Ad-hoc quote email, accounting improvements, AI lookup fix, and misc service updates

- Quotes: ad-hoc email modal on Quote Details lets staff send to an address not on file;
  QuotesController passes overrideEmail through to NotificationService
- Quotes/Details view: SMS consent display, email/SMS send button state based on consent
- Accounting module: AccountingDisplayHelpers for consistent ledger formatting;
  AccountsController + Accounts views improvements; AccountingEnums additions
- Bills/Expenses: AI account categorization fixes in BillsController and ExpensesController
- InventoryAiLookupService: TDS cure fallback no longer fires on AiAugmentFromUrl path
  (LookupByUrlAsync already has it built in — was double-fetching)
- PdfService: quote/invoice PDF updates
- PricingCalculationService: minor pricing logic fix
- QuoteProfile: mapping updates for new quote fields
- ApplicationDbContextModelSnapshot: catches up to all 4 migrations in this branch

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

src/PowderCoating.Web/Views/Accounts/Index.cshtml

@@ -156,7 +156,7 @@
                                     <span class="badge bg-secondary ms-1" title="System account — cannot be deleted">sys</span>
                                 }
                             </td>
-                            <td><span class="text-muted small">@acct.AccountSubType</span></td>
+                            <td><span class="text-muted small">@acct.AccountSubType.ToDisplayName()</span></td>
                             <td>
                                 @if (!string.IsNullOrEmpty(acct.ParentAccountName))
                                 {