Self-review M5/M6/UX1: accurate preview, invalidate on change, reset overrides

Fixes found reviewing the previous commit:

- M5 preview was inaccurate: loadCommandPreview omitted formatId/formatHasAudio
  and trim, so the "exact command" differed from what download() actually spawns
  whenever a probe-selected format or a trim range was set. toggleCommandPreview
  now mirrors download()'s StartDownloadOptions (format + trim included).
- Stale preview: a shown command only cleared on URL change. Now it also clears
  on kind, quality, format, trim, download-options change, and on probe — so the
  displayed command is never out of sync with the form.
- Command button is now a real toggle (Show command / Hide command) instead of a
  no-op "Command · shown" label.
- Per-download overrides are now one-shot: incognito + downloadOptions reset to
  defaults after a download, matching trim/schedule and preventing incognito from
  silently carrying into the next download.
- Style: replaced two inline style={{}} usages with makeStyles classes
  (commandError), hardcoded 'monospace' -> tokens.fontFamilyMonospace, dropped an
  unnecessary fragment, and let long command lines wrap (pre-wrap/break-all).

typecheck + 243 tests + eslint + prettier green.

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

src/renderer/src/components/DownloadBar.tsx

@@ -264,12 +264,20 @@ const useStyles = makeStyles({
     backgroundColor: tokens.colorNeutralBackground2,
     ...shorthands.borderRadius(tokens.borderRadiusLarge),
     border: `1px solid ${tokens.colorNeutralStroke2}`,
-    fontFamily: 'monospace',
+    fontFamily: tokens.fontFamilyMonospace,
     fontSize: tokens.fontSizeBase200,
     overflowX: 'auto',
+    whiteSpace: 'pre-wrap',
+    wordBreak: 'break-all',
     color: tokens.colorNeutralForeground1
   },
+  commandError: {
+    color: tokens.colorStatusDangerForeground1
+  },
   optionsPanel: {
+    display: 'flex',
+    flexDirection: 'column',
+    gap: '12px',
     padding: '12px',
     backgroundColor: tokens.colorNeutralBackground2,
     ...shorthands.borderRadius(tokens.borderRadiusLarge),
@@ -403,20 +411,28 @@ export function DownloadBar(): React.JSX.Element {
     setItemKinds({})
   }
 
-  async function loadCommandPreview(): Promise<void> {
+  // Fetch (or toggle off) the exact yt-dlp command line for the current form
-    const trimmed = url.trim()
+  // state. The options mirror what download() sends so the preview matches the
-    if (!trimmed) {
+  // command that will actually run -- including a probe-selected format and any
+  // trim spec (M5).
+  async function toggleCommandPreview(): Promise<void> {
+    if (commandPreview) {
       setCommandPreview(null)
       return
     }
+    const trimmed = url.trim()
+    if (!trimmed) return
     setPreviewLoading(true)
     try {
       const result = await window.api.previewCommand({
         id: 'preview',
         url: trimmed,
-        kind,
+        kind: usingFormats ? 'video' : kind,
-        quality,
+        quality: usingFormats && selectedFormat ? selectedFormat.label : quality,
-        options: downloadOptions
+        formatId: usingFormats ? selectedFormat?.id : undefined,
+        formatHasAudio: usingFormats ? selectedFormat?.hasAudio : undefined,
+        options: downloadOptions,
+        trim: trim.trim() || undefined
       })
       setCommandPreview(result)
     } catch (e) {
@@ -431,13 +447,15 @@ export function DownloadBar(): React.JSX.Element {
     // Any probed info -- or a duplicate warning -- is stale once the URL changes.
     if (info || probeError || playlist) clearProbe()
     if (dup) setDup(null)
-    if (commandPreview) setCommandPreview(null)
+    setCommandPreview(null)
     confirmDup.current = false
   }
 
   function onKindChange(next: MediaKind): void {
     setKind(next)
     setQuality(QUALITY_OPTIONS[next][0])
+    // The command changes with kind/quality, so any shown preview is now stale.
+    setCommandPreview(null)
   }
 
   async function fetchFormats(): Promise<void> {
@@ -447,6 +465,8 @@ export function DownloadBar(): React.JSX.Element {
     setProbeError(null)
     setInfo(null)
     setPlaylist(null)
+    // Probing may switch the URL to the format-picker path, changing the command.
+    setCommandPreview(null)
     try {
       const res = await window.api.probe(trimmed)
       if (res.ok && res.kind === 'playlist' && res.playlist) {
@@ -573,6 +593,11 @@ export function DownloadBar(): React.JSX.Element {
     setShowSchedule(false)
     setShowAdvanced(false)
     setCommandPreview(null)
+    // Per-download overrides are one-shot (like trim/schedule): reset so the next
+    // download starts from the global defaults, and incognito never silently
+    // carries over to a following download.
+    setIncognito(false)
+    setDownloadOptions(DEFAULT_DOWNLOAD_OPTIONS)
     clearProbe()
   }
 
@@ -814,7 +839,10 @@ export function DownloadBar(): React.JSX.Element {
               >
                 <Textarea
                   value={trim}
-                  onChange={(_, d) => setTrim(d.value)}
+                  onChange={(_, d) => {
+                    setTrim(d.value)
+                    setCommandPreview(null)
+                  }}
                   placeholder={'0:30-1:45\n3:00-3:30'}
                   resize="vertical"
                 />
@@ -855,22 +883,18 @@ export function DownloadBar(): React.JSX.Element {
               size="small"
               appearance="subtle"
               icon={previewLoading ? <Spinner size="tiny" /> : <WindowConsoleRegular />}
-              onClick={loadCommandPreview}
+              onClick={toggleCommandPreview}
               disabled={!url.trim() || previewLoading}
             >
-              {commandPreview ? 'Command · shown' : 'Show command'}
+              {commandPreview ? 'Hide command' : 'Show command'}
             </Button>
           </div>
           {commandPreview && (
             <div className={styles.commandPreviewPanel}>
               {commandPreview.ok ? (
-                <>
+                commandPreview.command
-                  <div>{commandPreview.command}</div>
-                </>
               ) : (
-                <div style={{ color: tokens.colorStatusDangerForeground1 }}>
+                <span className={styles.commandError}>Error: {commandPreview.error}</span>
-                  Error: {commandPreview.error}
-                </div>
               )}
             </div>
           )}
@@ -881,14 +905,15 @@ export function DownloadBar(): React.JSX.Element {
                 onChange={(_, d) => setIncognito(!!d.checked)}
                 label="Incognito mode (no logging, no history, no cookies)"
               />
-              <div style={{ marginTop: '12px' }}>
               <DownloadOptionsForm
                 value={downloadOptions}
-                  onChange={setDownloadOptions}
+                onChange={(next) => {
+                  setDownloadOptions(next)
+                  setCommandPreview(null)
+                }}
                 kind={kind}
               />
             </div>
-            </div>
           )}
         </div>
       )}
@@ -916,7 +941,10 @@ export function DownloadBar(): React.JSX.Element {
               size="large"
               value={selectedFormat?.id ?? ''}
               options={info.formats.map((f) => ({ value: f.id, label: f.label }))}
-              onChange={setFormatId}
+              onChange={(v) => {
+                setFormatId(v)
+                setCommandPreview(null)
+              }}
             />
           ) : (
             <Select
@@ -925,7 +953,10 @@ export function DownloadBar(): React.JSX.Element {
               size="large"
               value={quality}
               options={QUALITY_OPTIONS[kind].map((q) => ({ value: q, label: q }))}
-              onChange={setQuality}
+              onChange={(v) => {
+                setQuality(v)
+                setCommandPreview(null)
+              }}
             />
           )}
         </div>