Update Kagi search provider to support app launch with fallback (#5590)

- Add package name for Kagi mobile app (com.kagi.search)
- Change type from LOCAL to APP_AND_WEBSITE for unified behavior
- Add documentation explaining app-first, website-fallback approach

lawnchair/src/app/lawnchair/qsb/providers/Kagi.kt

@@ -3,14 +3,18 @@ package app.lawnchair.qsb.providers
 import app.lawnchair.qsb.ThemingMethod
 import com.android.launcher3.R
 
+/**
+ * Unified Kagi search provider that attempts to launch the Kagi mobile app first,
+ * and falls back to opening the Kagi website if the app is not installed.
+ */
 data object Kagi : QsbSearchProvider(
     id = "kagi",
     name = R.string.search_provider_kagi,
     icon = R.drawable.ic_kagi,
     themedIcon = R.drawable.ic_kagi_tinted,
     themingMethod = ThemingMethod.TINT,
-    packageName = "",
+    packageName = "com.kagi.search",
     website = "https://kagi.com",
-    type = QsbSearchProviderType.LOCAL,
+    type = QsbSearchProviderType.APP_AND_WEBSITE,
     sponsored = false,
 )