feat(discovery): bonjour beacons + bridge presence

apps/ios/Sources/Bridge/BonjourEscapeDecoder.swift

@@ -0,0 +1,34 @@
+import Foundation
+
+enum BonjourEscapeDecoder {
+    static func decode(_ input: String) -> String {
+        // mDNS / DNS-SD commonly escapes bytes in instance names as `\\DDD`
+        // (decimal-encoded), e.g. spaces are `\\032`.
+        var out = ""
+        var i = input.startIndex
+        while i < input.endIndex {
+            if input[i] == "\\",
+               let d0 = input.index(i, offsetBy: 1, limitedBy: input.index(before: input.endIndex)),
+               let d1 = input.index(i, offsetBy: 2, limitedBy: input.index(before: input.endIndex)),
+               let d2 = input.index(i, offsetBy: 3, limitedBy: input.index(before: input.endIndex)),
+               input[d0].isNumber,
+               input[d1].isNumber,
+               input[d2].isNumber
+            {
+                let digits = String(input[d0...d2])
+                if let value = Int(digits),
+                   let scalar = UnicodeScalar(value)
+                {
+                    out.append(Character(scalar))
+                    i = input.index(i, offsetBy: 4)
+                    continue
+                }
+            }
+
+            out.append(input[i])
+            i = input.index(after: i)
+        }
+        return out
+    }
+}
+