fix: check indentation with substring contains, not per-character

contains(where:) on String iterates Characters; comparing each to
multi-character strings like "\n    " is a type error. Use
tail.contains("\n    ") || tail.contains("\t") instead.

Co-authored-by: Rocky <hkgood@users.noreply.github.com>

OSGKeyboardShared/Services/AppContextDetector.swift

@@ -95,7 +95,7 @@ public struct AppContextDetector: Sendable {
             "if (", "if (", "} else", "} catch",
             "=> {", "-> {",
         ]
-        let hasIndentation = tail.contains(where: { $0 == "\n    " || $0 == "\t" })
+        let hasIndentation = tail.contains("\n    ") || tail.contains("\t")
         let hasCodeKeyword = codeKeywords.contains(where: { tail.contains($0) })
         if hasIndentation, hasCodeKeyword {
             return .code