Fix audit findings: budget editing, dead code, logging, multi-currency

- Add budget editing: updateBudget() API, edit button on budget cards,
  BudgetFormModal adapted for create/update (category locked on edit)
- Remove permanently-broken POST /auth/totp/verify stub and its unused
  TOTPVerifyRequest schema
- Wire getHoldingTransactions() to AssetDetail page — transaction history
  table now shows above the candlestick chart, sorted newest-first
- Fix multi-currency net worth in account_service: account balances are
  now converted to base_currency via ExchangeRate table before summing
- Replace silent bare pass exception handlers with logger.warning() in
  transactions.py (OCR/AI pipeline) and price_feed_service.py (search)
  — ValueError in date/number regex parsing left silent (control flow)

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

frontend/src/pages/investments/AssetDetail.tsx

@@ -1,6 +1,6 @@
 import { useParams, Link } from "react-router-dom";
 import { useQuery } from "@tanstack/react-query";
-import { getPriceHistory, getPortfolio } from "@/api/investments";
+import { getPriceHistory, getPortfolio, getHoldingTransactions } from "@/api/investments";
 import { formatCurrency } from "@/utils/currency";
 import { useUiStore } from "@/store/uiStore";
 import { cn } from "@/utils/cn";
@@ -20,6 +20,12 @@ export default function AssetDetail() {
     enabled: !!assetId,
   });
 
+  const { data: transactions = [] } = useQuery({
+    queryKey: ["holding-transactions", holding?.id],
+    queryFn: () => getHoldingTransactions(holding!.id),
+    enabled: !!holding?.id,
+  });
+
   const dates = prices.map(p => p.date);
   const opens = prices.map(p => p.open ?? p.close);
   const highs = prices.map(p => p.high ?? p.close);
@@ -73,6 +79,62 @@ export default function AssetDetail() {
         </div>
       )}
 
+      {/* Transaction history */}
+      {holding && (
+        <div className="bg-card border border-border rounded-xl overflow-hidden">
+          <div className="px-4 py-3 border-b border-border">
+            <p className="text-sm font-medium">Transaction History</p>
+          </div>
+          {transactions.length === 0 ? (
+            <p className="text-sm text-muted-foreground text-center py-8">No transactions recorded</p>
+          ) : (
+            <table className="w-full text-sm">
+              <thead>
+                <tr className="text-xs text-muted-foreground uppercase tracking-wider border-b border-border">
+                  <th className="text-left px-4 py-2">Date</th>
+                  <th className="text-left px-4 py-2">Type</th>
+                  <th className="text-right px-4 py-2">Quantity</th>
+                  <th className="text-right px-4 py-2">Price</th>
+                  <th className="text-right px-4 py-2 hidden sm:table-cell">Fees</th>
+                  <th className="text-right px-4 py-2">Total</th>
+                </tr>
+              </thead>
+              <tbody>
+                {[...transactions].sort((a, b) => b.date.localeCompare(a.date)).map((t) => {
+                  const isBuy = t.type === "buy" || t.type === "transfer_in";
+                  const isSell = t.type === "sell" || t.type === "transfer_out";
+                  return (
+                    <tr key={t.id} className="border-b border-border/50 last:border-0 hover:bg-secondary/20 transition-colors">
+                      <td className="px-4 py-2.5 tabular-nums text-muted-foreground">{t.date}</td>
+                      <td className="px-4 py-2.5">
+                        <span className={cn(
+                          "inline-flex items-center px-2 py-0.5 rounded text-xs font-medium",
+                          isBuy ? "bg-success/15 text-success" :
+                          isSell ? "bg-destructive/15 text-destructive" :
+                          "bg-secondary text-muted-foreground"
+                        )}>
+                          {t.type.replace("_", " ")}
+                        </span>
+                      </td>
+                      <td className="px-4 py-2.5 text-right tabular-nums">{Number(t.quantity).toLocaleString()}</td>
+                      <td className="px-4 py-2.5 text-right tabular-nums">{formatCurrency(t.price, t.currency)}</td>
+                      <td className="px-4 py-2.5 text-right tabular-nums hidden sm:table-cell text-muted-foreground">
+                        {t.fees > 0 ? formatCurrency(t.fees, t.currency) : "—"}
+                      </td>
+                      <td className={cn("px-4 py-2.5 text-right tabular-nums font-medium",
+                        isBuy ? "text-destructive" : isSell ? "text-success" : ""
+                      )}>
+                        {isSell ? "+" : isBuy ? "-" : ""}{formatCurrency(t.total_amount, t.currency)}
+                      </td>
+                    </tr>
+                  );
+                })}
+              </tbody>
+            </table>
+          )}
+        </div>
+      )}
+
       {/* Candlestick chart */}
       <div className="bg-card border border-border rounded-xl p-4">
         <p className="text-sm font-medium mb-3">Price History (1 Year)</p>