feat(companion): add appState, eraseText, pressKey runner handlers

The Go runner transport already calls these methods; the in-device runner
implemented them only latently. They become load-bearing on the device
path, where the hybrid's legacy-companion fallback is absent. Backward
compatible: the simulator hybrid never calls them.

companion/Sources/Server.swift

@@ -122,6 +122,19 @@ final class Server {
             let bundleIdentifier = params["bundleId"] as? String ?? currentBundleIdentifier
             try TextInput.type(text: text, replace: replace, bundleIdentifier: bundleIdentifier)
             return ["ok": true]
+        case "eraseText":
+            let count = params["count"] as? Int ?? 0
+            let bundleIdentifier = params["bundleId"] as? String ?? currentBundleIdentifier
+            try TextInput.erase(count: count, bundleIdentifier: bundleIdentifier)
+            return ["ok": true]
+        case "pressKey":
+            let key = params["key"] as? String ?? ""
+            let bundleIdentifier = params["bundleId"] as? String ?? currentBundleIdentifier
+            try TextInput.pressKey(key: key, bundleIdentifier: bundleIdentifier)
+            return ["ok": true]
+        case "appState":
+            let bundleIdentifier = params["bundleId"] as? String ?? currentBundleIdentifier
+            return ["state": AppLifecycle.state(bundleIdentifier: bundleIdentifier)]
         case "screenshot":
             return try screenshot()
         default: