fix(payment): crash on open due to amount.toFixed on numeric string

feat(shared): tag filter on shared transactions list

src/app/api/shared-transactions/route.ts

@@ -6,6 +6,8 @@ export async function GET(req: NextRequest) {
   const user = await getCurrentUser(req);
   if (!user) return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
 
-  const transactions = await getSharedTransactions(user.id);
+  const tagParam = req.nextUrl.searchParams.get("tag_ids");
+  const tagIds = tagParam ? tagParam.split(",").map(Number).filter(Boolean) : undefined;
+  const transactions = await getSharedTransactions(user.id, tagIds);
   return NextResponse.json(transactions);
 }

src/app/shared/page.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { useState } from "react";
+import { useState, useRef, useEffect } from "react";
 import {
   useSharedTransactions,
   useParticipantBalances,
@@ -9,6 +9,7 @@ import {
   usePaymentHistory,
   useDeletePayment,
   useCurrentUser,
+  useTags,
   type SplitPayment,
 } from "@/lib/hooks";
 import type { SharedTransactionRow } from "@/lib/queries";
@@ -24,6 +25,55 @@ function formatAmount(n: number, type?: string) {
   return type && !SPEND_TYPES.has(type) ? `+${formatted}` : formatted;
 }
 
+// ── Tag multi-select ──────────────────────────────────────────────────────────
+function TagFilter({ value, onChange }: { value: string[]; onChange: (v: string[]) => void }) {
+  const { data: tags = [] } = useTags();
+  const [open, setOpen] = useState(false);
+  const ref = useRef<HTMLDivElement>(null);
+
+  useEffect(() => {
+    function handler(e: MouseEvent) {
+      if (ref.current && !ref.current.contains(e.target as Node)) setOpen(false);
+    }
+    document.addEventListener("mousedown", handler);
+    return () => document.removeEventListener("mousedown", handler);
+  }, []);
+
+  if (!tags.length) return null;
+
+  const toggle = (id: string) =>
+    onChange(value.includes(id) ? value.filter((x) => x !== id) : [...value, id]);
+
+  const label = value.length === 0 ? "All Tags"
+    : value.length === 1 ? (tags.find((t) => String(t.id) === value[0])?.name ?? "1 tag")
+    : `${value.length} tags`;
+
+  return (
+    <div ref={ref} className="relative">
+      <button
+        type="button"
+        onClick={() => setOpen((v) => !v)}
+        className={`border rounded px-3 py-1.5 text-sm flex items-center gap-2 min-w-[120px] bg-zinc-900 ${value.length > 0 ? "border-indigo-500 text-white" : "border-zinc-700 text-zinc-400"}`}
+      >
+        <span className="flex-1 text-left">{label}</span>
+        <span className="text-zinc-500 text-xs">▾</span>
+      </button>
+      {open && (
+        <div className="absolute top-full mt-1 z-20 bg-zinc-900 border border-zinc-700 rounded-lg shadow-xl min-w-[160px] max-h-56 overflow-y-auto">
+          {tags.map((t) => (
+            <label key={t.id} className="flex items-center gap-2 px-3 py-1.5 hover:bg-zinc-800 cursor-pointer text-sm">
+              <input type="checkbox" checked={value.includes(String(t.id))} onChange={() => toggle(String(t.id))}
+                className="accent-indigo-500 flex-shrink-0" />
+              <span className="w-2 h-2 rounded-full flex-shrink-0" style={{ backgroundColor: t.color }} />
+              {t.name}
+            </label>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}
+
 // ── Add Participant ───────────────────────────────────────────────────────────
 function AddParticipantForm({ onDone }: { onDone: () => void }) {
   const [name, setName] = useState("");
@@ -207,7 +257,8 @@ function PaymentHistory({ participantId, currentUserId }: { participantId: numbe
 
 // ── Main page ─────────────────────────────────────────────────────────────────
 export default function SharedPage() {
-  const { data: transactions = [], isLoading: txLoading } = useSharedTransactions();
+  const [tagIds, setTagIds] = useState<string[]>([]);
+  const { data: transactions = [], isLoading: txLoading } = useSharedTransactions(tagIds);
   const { data: balances = [], isLoading: balLoading } = useParticipantBalances();
   const { data: me } = useCurrentUser();
   const [addingParticipant, setAddingParticipant] = useState(false);
@@ -216,15 +267,18 @@ export default function SharedPage() {
 
   return (
     <div className="space-y-6">
-      <div className="flex items-center justify-between">
+      <div className="flex items-center justify-between gap-3">
         <h2 className="text-xl font-semibold">Shared Expenses</h2>
+        <div className="flex items-center gap-2 ml-auto">
+          <TagFilter value={tagIds} onChange={setTagIds} />
           {!addingParticipant && (
             <button onClick={() => setAddingParticipant(true)}
-            className="text-sm px-3 py-1.5 bg-zinc-800 hover:bg-zinc-700 text-zinc-300 rounded-lg">
+              className="text-sm px-3 py-1.5 bg-zinc-800 hover:bg-zinc-700 text-zinc-300 rounded-lg whitespace-nowrap">
               + Add Participant
             </button>
           )}
         </div>
+      </div>
 
       {addingParticipant && <AddParticipantForm onDone={() => setAddingParticipant(false)} />}
 

src/app/transactions/page.tsx

@@ -225,7 +225,7 @@ function MarkAsPaymentModal({
   const [direction, setDirection] = useState<"received" | "sent">(
     SPEND_TYPES.has(transaction.transaction_type) ? "sent" : "received"
   );
-  const [amount, setAmount] = useState(transaction.amount.toFixed(2));
+  const [amount, setAmount] = useState(Number(transaction.amount).toFixed(2));
   const [date, setDate] = useState(transaction.transaction_date.slice(0, 10));
   const [notes, setNotes] = useState("");
   const [error, setError] = useState("");

src/lib/hooks.ts

@@ -208,11 +208,12 @@ export function useParticipantBalances() {
   });
 }
 
-export function useSharedTransactions() {
+export function useSharedTransactions(tagIds?: string[]) {
   return useQuery({
-    queryKey: ["shared-transactions"],
+    queryKey: ["shared-transactions", tagIds],
     queryFn: async () => {
-      const res = await fetch("/api/shared-transactions");
+      const params = tagIds?.length ? `?tag_ids=${tagIds.join(",")}` : "";
+      const res = await fetch(`/api/shared-transactions${params}`);
       return res.json();
     },
   });

src/lib/queries.ts

@@ -335,7 +335,14 @@ export async function getTags() {
   `);
 }
 
-export async function getSharedTransactions(ownerId: number) {
+export async function getSharedTransactions(ownerId: number, tagIds?: number[]) {
+  const params: unknown[] = [ownerId];
+  let tagClause = "";
+  if (tagIds?.length) {
+    params.push(tagIds);
+    tagClause = `AND EXISTS (SELECT 1 FROM transaction_tags tt WHERE tt.transaction_id = t.id AND tt.tag_id = ANY($2::int[]))`;
+  }
+
   const rows = await queryRaw<TransactionRow & { split_data: string }>(`
     SELECT t.*,
       o.category_override, o.merchant_normalized as merchant_override, o.notes,
@@ -358,17 +365,16 @@ export async function getSharedTransactions(ownerId: number) {
     LEFT JOIN statements s ON s.id = t.statement_id
     LEFT JOIN participants p_owner ON p_owner.id = COALESCE(t.owner_id, s.owner_id)
     WHERE (
-        -- I own this transaction and at least one other person has a split
         COALESCE(t.owner_id, s.owner_id) = $1
         AND EXISTS (SELECT 1 FROM transaction_splits ts2 WHERE ts2.transaction_id = t.id AND ts2.participant_id != $1)
       ) OR (
-        -- Someone else owns this transaction and I have a split on it
         COALESCE(t.owner_id, s.owner_id) != $1
         AND EXISTS (SELECT 1 FROM transaction_splits ts_me WHERE ts_me.transaction_id = t.id AND ts_me.participant_id = $1)
       )
+    ${tagClause}
     GROUP BY t.id, o.category_override, o.merchant_normalized, o.notes, s.bank_name, s.owner_id, p_owner.name
     ORDER BY t.transaction_date DESC
-  `, [ownerId]);
+  `, params);
 
   return rows.map((r) => ({
     ...r,