build: add ESLint to script/lint and containerize linting (closes #152)

src/shared/prices.js

@@ -21,7 +21,7 @@ async function refreshPrices() {
         const fetched = await getTopTokenPrices(25);
         Object.assign(prices, fetched);
         lastFetchedAt = now;
-    } catch (e) {
+    } catch {
         // prices stay stale on error
     }
 }

src/shared/txValidation.js

@@ -82,7 +82,7 @@ function toFixedPoint(value) {
     if (text === "") return null;
     try {
         return parseUnits(text, SCALE_DECIMALS);
-    } catch (e) {
+    } catch {
         return null;
     }
 }

src/shared/uniswap.js

@@ -102,6 +102,11 @@ function decodeV2SwapExactIn(input) {
 // Decode V2_SWAP_EXACT_OUT (command 0x09) input bytes.
 // ABI: (address recipient, uint256 amountOut, uint256 amountInMax,
 //        address[] path, bool payerIsUser)
+//
+// Nothing calls this: decode() has no 0x09 arm, so a V2 exact-out swap gets
+// its command name and no token or amount detail. Kept for the fix, which is
+// https://git.eeqj.de/sneak/AutistMask/issues/283.
+// eslint-disable-next-line no-unused-vars
 function decodeV2SwapExactOut(input) {
     try {
         const d = coder.decode(

src/shared/vault.js

@@ -57,7 +57,7 @@ async function cryptoBackend() {
     try {
         await WebAssembly.compile(EMPTY_WASM_MODULE);
         return "wasm";
-    } catch (_) {
+    } catch {
         return "asmjs";
     }
 }