fix: name a tracked or explorer-known token instead of "Unknown token" (closes #323)

The approval and transaction-status screens read a token's scale from the
bundled list, the tokens the user tracks, then the block explorer, but read
its symbol from the bundled list alone. A token the user added by hand was
scaled correctly yet labelled "Unknown token", and a non-bundled ERC-20 was
carried onto the wait screen as ETH.

resolveTokenSymbol() now draws the symbol through the same sources and
precedence as the scale, and the ERC-20 and Uniswap swap lines both use it. A
tracked or explorer-reported name stays subject to the spoof rule, so it
cannot claim a bundled or native ticker.

Folds in #354.

Model: opus-4-8

tests/uniswapUnknownDecimals.test.js

@@ -98,12 +98,13 @@ describe("a swap of a token outside the bundled list", () => {
         state.trackedTokens = [
             { address: NOVEL, symbol: "NOVEL", decimals: 6 },
         ];
-        expect(swapDetail(data(), "Amount").value).toBe("1000.0000");
+        // The tracked entry names the token as well as scaling it (issue #323).
+        expect(swapDetail(data(), "Amount").value).toBe("1000.0000 NOVEL");
     });
 
     test("shows the true quantity from the explorer's decimals", () => {
         state.wallets = walletsHolding(NOVEL, "6");
-        expect(swapDetail(data(), "Amount").value).toBe("1000.0000");
+        expect(swapDetail(data(), "Amount").value).toBe("1000.0000 NOVEL");
     });
 
     test("refuses to format when nothing knows the scale", () => {
@@ -140,7 +141,7 @@ describe("the Min. received line takes the same rule", () => {
             { address: NOVEL_OUT, symbol: "NOVEL", decimals: 6 },
         ];
         const data = swapData(WETH, HALF_WETH, NOVEL_OUT, THOUSAND_AT_SIX);
-        expect(swapDetail(data, "Min. received").value).toBe("1000.0000");
+        expect(swapDetail(data, "Min. received").value).toBe("1000.0000 NOVEL");
     });
 });