Add card style option for Home shortcut cards

Adds a Style picker (Plain / Accent / Colorful) to the Customize Home
sheet, shown when the shortcuts layout is Cards. Defaults to Plain.

- Plain: current look (light accent tint + accent border)
- Accent: solid accent fill, white icon/text
- Colorful: solid fill with a fixed color per shortcut type

The filled styles use a Reminders-style layout (icon top-leading, count
top-trailing, title anchored to the bottom) with a subtle gradient sheen
over the fill color. Cards without a meaningful count (Open Link, Remote,
Subscriptions, instance content, media sources) hide the number; Remote
shows its status dot in the top-right slot instead.

Persisted via SettingsKey.homeShortcutCardStyle, mirroring the existing
homeShortcutLayout accessor.

Yattee/Localizable.xcstrings

@@ -4192,6 +4192,50 @@
         }
       }
     },
+    "home.settings.shortcuts.style" : {
+      "comment" : "Label for shortcuts card style picker in library settings",
+      "localizations" : {
+        "en" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "Style"
+          }
+        }
+      }
+    },
+    "home.shortcuts.style.accent" : {
+      "comment" : "Accent card style option",
+      "localizations" : {
+        "en" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "Accent"
+          }
+        }
+      }
+    },
+    "home.shortcuts.style.colorful" : {
+      "comment" : "Colorful card style option",
+      "localizations" : {
+        "en" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "Colorful"
+          }
+        }
+      }
+    },
+    "home.shortcuts.style.plain" : {
+      "comment" : "Plain card style option",
+      "localizations" : {
+        "en" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "Plain"
+          }
+        }
+      }
+    },
     "home.settings.sourceDisabled" : {
 
     },