Fix L106/L107/L122: unify refresh icons, spinner size, busy-button feedback

L106: Established the convention — ArrowClockwise = retry/redo a local action
      (retry-all, re-download, retry queue item); ArrowSync = network sync/
      update (sync sources, reindex, check/apply updates). Flipped the two
      misclassified sites (LibraryView "check for new" sync, SettingsView
      "Update yt-dlp") to ArrowSync and dropped the now-unused imports.

L107: QueueItem queued-row Spinner was size="extra-tiny"; every other spinner
      is "tiny". Standardized to "tiny".

L122: The app-update and yt-dlp-update buttons showed "Checking…"/"Updating…"
      in the label AND a separate sibling Spinner. Folded the spinner into the
      button icon (icon swaps to Spinner while busy), matching DownloadBar/
      LibraryView, and removed the redundant sibling Spinner.

typecheck + 242 tests + eslint green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/renderer/src/components/LibraryView.tsx

@@ -16,7 +16,6 @@ import {
 import {
   SearchRegular,
   ArrowSyncRegular,
-  ArrowClockwiseRegular,
   DeleteRegular,
   ArrowDownloadRegular,
   ChevronDownRegular,
@@ -551,7 +550,7 @@ export function LibraryView(): React.JSX.Element {
         <Button
           size="small"
           appearance="secondary"
-          icon={syncing ? <Spinner size="tiny" /> : <ArrowClockwiseRegular />}
+          icon={syncing ? <Spinner size="tiny" /> : <ArrowSyncRegular />}
           onClick={onCheckNew}
           disabled={syncing || watchedCount === 0}
         >

src/renderer/src/components/QueueItem.tsx

@@ -204,7 +204,7 @@ export const QueueItem = memo(function QueueItem({
 
         {item.status === 'queued' && (
           <div className={styles.progressRow}>
-            <Spinner size="extra-tiny" />
+            <Spinner size="tiny" />
             <Caption1 className={styles.stats}>Waiting to start…</Caption1>
           </div>
         )}

src/renderer/src/components/SettingsView.tsx

@@ -25,7 +25,6 @@ import {
   GlobeRegular,
   CookiesRegular,
   CodeRegular,
-  ArrowClockwiseRegular,
   DocumentArrowDownRegular,
   DocumentArrowUpRegular,
   BugRegular,
@@ -1039,13 +1038,12 @@ export function SettingsView(): React.JSX.Element {
 
         <div className={styles.folderRow}>
           <Button
-            icon={<ArrowSyncRegular />}
+            icon={appChecking ? <Spinner size="tiny" /> : <ArrowSyncRegular />}
             onClick={checkAppUpdate}
             disabled={appChecking || appDownloading}
           >
             {appChecking ? 'Checking…' : 'Check for updates'}
           </Button>
-          {appChecking && <Spinner size="tiny" />}
         </div>
 
         {(updateToken.trim() !== '' || !!appUpdError) && (
@@ -1175,10 +1173,13 @@ export function SettingsView(): React.JSX.Element {
           />
         </Field>
         <div className={styles.folderRow}>
-          <Button icon={<ArrowClockwiseRegular />} onClick={runUpdate} disabled={updating}>
+          <Button
+            icon={updating ? <Spinner size="tiny" /> : <ArrowSyncRegular />}
+            onClick={runUpdate}
+            disabled={updating}
+          >
             {updating ? 'Updating…' : 'Update yt-dlp'}
           </Button>
-          {updating && <Spinner size="tiny" />}
         </div>
         {updateResult?.ok && (
           <Text style={{ fontFamily: tokens.fontFamilyMonospace, whiteSpace: 'pre-wrap' }}>