feat(sidebar): restore PR state color, swap badge order, brighten checks on hover

- PR icon color reflects merge state (open/merged/closed) via the
  existing getWorkspacePrIconColor helper.
- PR badge is rendered before the failed-checks badge in the workspace
  row.
- Hovering the PR badge swaps the GitPullRequest icon for ExternalLink
  in place (same size, no layout shift) and removes the trailing arrow.
- Hovering the checks row in the workspace hover card brightens the
  icon and "Checks" label to foreground.

packages/app/src/components/workspace-hover-card.tsx

@@ -306,14 +306,24 @@ function WorkspaceHoverCardContent({
                     badgeLabel = `${checks.length} passed`;
                   }
 
+                  const iconColor = hovered
+                    ? theme.colors.foreground
+                    : theme.colors.foregroundMuted;
                   return (
                     <>
                       {hovered ? (
-                        <ExternalLink size={12} color={theme.colors.foregroundMuted} />
+                        <ExternalLink size={12} color={iconColor} />
                       ) : (
-                        <GitHubIcon size={12} color={theme.colors.foregroundMuted} />
+                        <GitHubIcon size={12} color={iconColor} />
                       )}
-                      <Text style={styles.checksSummaryLabel}>Checks</Text>
+                      <Text
+                        style={[
+                          styles.checksSummaryLabel,
+                          hovered && styles.checksSummaryLabelHovered,
+                        ]}
+                      >
+                        Checks
+                      </Text>
                       <View style={styles.checksSummaryCounts}>
                         <View style={[styles.checksDot, { backgroundColor: badgeColor }]} />
                         <Text style={[styles.checksStatusText, { color: badgeColor }]}>
@@ -395,6 +405,9 @@ const styles = StyleSheet.create((theme) => ({
     fontWeight: theme.fontWeight.normal,
     color: theme.colors.foregroundMuted,
   },
+  checksSummaryLabelHovered: {
+    color: theme.colors.foreground,
+  },
   checksSummaryCounts: {
     flexDirection: "row",
     alignItems: "center",