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/uniswapTokenOut.test.js

@@ -78,15 +78,20 @@ describe("a swap to a token absent from the bundled list", () => {
         );
     });
 
-    test("names the address when the scale is known but the symbol is not", () => {
+    test("names the tracked symbol alongside the address (issue #323)", () => {
+        // The tracked entry supplies both halves now: the scale, and the
+        // symbol the output line is named by. Before #323 the symbol was read
+        // from the bundled list alone, so this line fell back to the address.
         const sources = {
             trackedTokens: [
                 { address: NOVEL_OUT, symbol: "NOVEL", decimals: 6 },
             ],
         };
-        expect(detail(data(), "Token Out", sources).value).toBe(NOVEL_OUT);
+        expect(detail(data(), "Token Out", sources).value).toBe(
+            "NOVEL (" + NOVEL_OUT + ")",
+        );
         expect(detail(data(), "Min. received", sources).value).toBe(
-            "1000.0000",
+            "1000.0000 NOVEL",
         );
     });
 });