chore: add JS/ESLint toolchain, refactor onclick to event delegation

- Add ESLint config for web/ui (flat config, golangci-lint-compatible)
- Add js-lint task to mise.toml (npm run lint in web/ui)
- Add ESLint check to check-toolchain.sh
- Add .golangci.yml for golangci-lint v2 with correct exclusions
- Refactor app.js: replace inline onclick with data-action + event delegation
- Add null checks and HTTP status checks to browseWavs
- Add web/ui/node_modules/ to .gitignore

web/ui/app.js

@@ -46,8 +46,8 @@ function renderResults(items) {
         <span>${r.downloads.toLocaleString()} downloads</span>
       </div>
       <div class="actions">
-        <button class="btn-dl" onclick="downloadItem('${esc(r.identifier)}')">Download ISOs</button>
-        <button class="btn-list" onclick="listItem('${esc(r.identifier)}')">List Files</button>
+        <button class="btn-dl" data-action="download" data-identifier="${esc(r.identifier)}">Download ISOs</button>
+        <button class="btn-list" data-action="list" data-identifier="${esc(r.identifier)}">List Files</button>
       </div>
       <div id="list-${sanitize(r.identifier)}" class="file-list"></div>
     </div>
@@ -218,7 +218,7 @@ async function browseWavs() {
     list.innerHTML = data.map(f => `
       <div class="wav-item" data-file="${esc(f)}">
         <span class="wav-name" title="${esc(f)}">${esc(f)}</span>
-        <button class="wav-play-btn" onclick="playWav('${esc(f)}')">Play</button>
+        <button class="wav-play-btn" data-action="play" data-wav="${esc(f)}">Play</button>
       </div>
     `).join('');
   } catch (e) {
@@ -332,3 +332,17 @@ function formatBytes(bytes) {
 
 // Initial load
 doSearch();
+
+// Event delegation for dynamically generated buttons
+document.addEventListener('click', function(e) {
+  const btn = e.target.closest('[data-action]');
+  if (!btn) return;
+  const action = btn.dataset.action;
+  if (action === 'download') {
+    downloadItem(btn.dataset.identifier);
+  } else if (action === 'list') {
+    listItem(btn.dataset.identifier);
+  } else if (action === 'play') {
+    playWav(btn.dataset.wav);
+  }
+});