Fix L67/L86: Onboarding Skip button; clear hidden selections on filter change

L67: Onboarding now has a 'Skip' button alongside 'Get started', both in a
     right-aligned flex row. Both call update({hasCompletedOnboarding:true})
     so the behavior is the same — Skip just reads as optional for users who
     want to get started immediately without reading the tips.

L86: HistoryView now clears any selected IDs that are no longer visible when
     the filter (query or kind) changes. A useEffect on `filtered` intersects
     the current selection with the new visible set and calls setSelected only
     if the size actually changed (avoids re-renders when the filter doesn't
     affect the selection).

typecheck + 242 tests green.

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

src/renderer/src/components/HistoryView.tsx

@@ -1,4 +1,4 @@
-import { useMemo, useState } from 'react'
+import { useEffect, useMemo, useState } from 'react'
 import {
   Text,
   Caption1,
@@ -173,6 +173,16 @@ export function HistoryView(): React.JSX.Element {
     })
   }, [entries, query, kindFilter])
 
+  // Clear selections that are no longer visible after a filter change (L86).
+  useEffect(() => {
+    if (selected.size === 0) return
+    const visible = new Set(filtered.map((h) => h.id))
+    setSelected((prev) => {
+      const next = new Set([...prev].filter((id) => visible.has(id)))
+      return next.size === prev.size ? prev : next
+    })
+  }, [filtered])
+
   function redownload(h: HistoryEntry): void {
     // Strip compound format labels ("720p · mp4 · 184 MB" → "720p") when there is
     // no stored formatId, so videoFormat() can still match the preset (H5).

src/renderer/src/components/Onboarding.tsx

@@ -1,4 +1,4 @@
-import {
+import {
   Card,
   Title2,
   Body1,
@@ -72,6 +72,11 @@ const useStyles = makeStyles({
     flexShrink: 0,
     marginTop: '2px',
     color: tokens.colorCompoundBrandForeground1
+  },
+  btnRow: {
+    display: 'flex',
+    justifyContent: 'flex-end',
+    gap: '8px'
   }
 })
 
@@ -126,13 +131,21 @@ export function Onboarding(): React.JSX.Element {
           ))}
         </div>
 
-        <Button
-          appearance="primary"
-          icon={<RocketRegular />}
-          onClick={() => update({ hasCompletedOnboarding: true })}
-        >
-          Get started
-        </Button>
+        <div className={styles.btnRow}>
+          <Button
+            appearance="subtle"
+            onClick={() => update({ hasCompletedOnboarding: true })}
+          >
+            Skip
+          </Button>
+          <Button
+            appearance="primary"
+            icon={<RocketRegular />}
+            onClick={() => update({ hasCompletedOnboarding: true })}
+          >
+            Get started
+          </Button>
+        </div>
       </Card>
     </div>
   )