Normalize shell and patch tool cards

app/androidApp/src/main/kotlin/com/example/aiapp/CodeFence.kt

@@ -160,6 +160,7 @@ private val FENCE_LANGUAGES: Map<String, Language> =
         "shell" to Language.SHELL,
         "zsh" to Language.SHELL,
         "console" to Language.SHELL,
+        "diff" to Language.DIFF,
         "python" to Language.PYTHON,
         "py" to Language.PYTHON,
         "javascript" to Language.JAVASCRIPT,