fix: hide explorer action for inbox links

frontend/src/App.svelte

@@ -902,6 +902,11 @@
     return item?.sourceKind || item?.captureKind || item?.type || ''
   }
 
+  function canShowInboxArtifactInFolder(item) {
+    const kind = inboxArtifactKind(item)
+    return kind !== 'url' && item?.type !== 'link'
+  }
+
   function fileRecordToPreviewItem(item, record) {
     return {
       id: item.id,
@@ -2584,7 +2589,9 @@
                   {/if}
                   <button class="btn btn-sm btn-primary" on:click|stopPropagation={() => openAssignInbox(item)}>{t('inbox.assign')}</button>
                   <button class="btn btn-sm" on:click|stopPropagation={() => openInboxArtifact(item)}>{t('common.open')}</button>
-                  <button class="btn btn-sm" on:click|stopPropagation={() => openNodeFolder(item)}>{t('file.showInExplorer')}</button>
+                  {#if canShowInboxArtifactInFolder(item)}
+                    <button class="btn btn-sm" on:click|stopPropagation={() => openNodeFolder(item)}>{t('file.showInExplorer')}</button>
+                  {/if}
                   <button class="btn btn-sm btn-danger" on:click|stopPropagation={() => confirmDeleteInbox(item)}>{t('common.delete')}</button>
                 </div>
               </div>

scripts/check-gui-render.mjs

@@ -144,6 +144,7 @@ async function runReadyScenario(cdp, url) {
   await clickText(cdp, '.inbox-header .btn', 'Вставить из буфера')
   await assertText(cdp, 'example.test', 'inbox: clipboard URL captured')
   await assertText(cdp, 'Ссылка', 'inbox: clipboard URL kind visible')
+  await assertInboxItemButtonAbsent(cdp, 'example.test', 'Показать в проводнике', 'inbox: link has no explorer action')
   await clickInboxItemButton(cdp, 'example.test', 'Открыть')
   await assertEval(cdp, `window.__VERSTAK_GUI_SMOKE__.state.openedUrls.includes('https://example.test/from-clipboard')`, 'inbox: open URL launches external URL')
   await clickInboxItemButton(cdp, 'example.test', 'Разложить')
@@ -485,6 +486,19 @@ async function clickInboxItemButton(cdp, title, buttonText) {
   await sleep(250)
 }
 
+async function assertInboxItemButtonAbsent(cdp, title, buttonText, label) {
+  await assertEval(cdp, `
+    (() => {
+      const norm = (value) => (value || '').replace(/\\s+/g, ' ').trim();
+      const row = [...document.querySelectorAll('.inbox-item')]
+        .find((node) => norm(node.innerText || node.textContent).includes(${JSON.stringify(title)}));
+      if (!row) return false;
+      return ![...row.querySelectorAll('button')]
+        .some((node) => norm(node.innerText || node.textContent).includes(${JSON.stringify(buttonText)}));
+    })()
+  `, label)
+}
+
 async function evalValue(cdp, expression) {
   const result = await cdp.send('Runtime.evaluate', {
     expression,