feat(frontend): increase ICPSwap minimum TVL threshold to 500 USD

Tokens like USDC have ICPSwap pools with low TVL whose prices are
unreliable. Raise the cutoff from 10 to 500 USD so we fall through to
"no fallback price" instead of feeding bad rates to the user.

Author: sbpublic

src/frontend/src/lib/utils/exchange.utils.ts

@@ -31,7 +31,7 @@ export const usdValue = ({
 			) * exchangeRate
 		: Number(ZERO);
 
-const ICPSWAP_MIN_TVL_USD = 10;
+const ICPSWAP_MIN_TVL_USD = 500;
 
 export const formatIcpSwapToCoingeckoPrices = (
 	tokens: IcpSwapToken[]

src/frontend/src/tests/lib/utils/exchange.utils.spec.ts

@@ -72,7 +72,7 @@ describe('exchange.utils', () => {
 		it('skips token where tvlUSD is exactly at the threshold', () => {
 			const mock = createMockIcpSwapToken({
 				price: '1.230000000000000000',
-				tvlUSD: '10.000000000000000000'
+				tvlUSD: '500.000000000000000000'
 			});
 			const result = formatIcpSwapToCoingeckoPrices([mock]);
 
@@ -83,7 +83,7 @@ describe('exchange.utils', () => {
 			const mock = createMockIcpSwapToken({
 				tokenLedgerId: MOCK_CANISTER_ID_1,
 				price: '1.230000000000000000',
-				tvlUSD: '10.010000000000000000'
+				tvlUSD: '500.010000000000000000'
 			});
 			const result = formatIcpSwapToCoingeckoPrices([mock]);