refactor(camera): centralize JPEG transcode cap

apps/shared/OpenClawKit/Sources/OpenClawKit/PhotoCapture.swift

@@ -0,0 +1,19 @@
+import Foundation
+
+public enum PhotoCapture {
+    public static func transcodeJPEGForGateway(
+        rawData: Data,
+        maxWidthPx: Int,
+        quality: Double,
+        maxPayloadBytes: Int = 5 * 1024 * 1024
+    ) throws -> (data: Data, widthPx: Int, heightPx: Int) {
+        // Base64 inflates payloads by ~4/3; cap encoded bytes so the payload stays under maxPayloadBytes (API limit).
+        let maxEncodedBytes = (maxPayloadBytes / 4) * 3
+        return try JPEGTranscoder.transcodeToJPEG(
+            imageData: rawData,
+            maxWidthPx: maxWidthPx,
+            quality: quality,
+            maxBytes: maxEncodedBytes)
+    }
+}
+