test: use v2 packet for regression test and add limit note

localPackages/BitFoundation/Sources/BitFoundation/FileTransferLimits.swift

@@ -7,6 +7,7 @@ public enum FileTransferLimits {
     /// Compressed images after downscaling should comfortably fit under this budget.
     public static let maxImageBytes: Int = 512 * 1024 // 512 KiB
     /// Worst-case size once TLV metadata and binary packet framing are included for the largest payloads.
+    /// Note: This is now a hard expanded-size ceiling rather than the old tlv+frame formula.
     /// MUST stay in sync with AppConstants.Protocol.MAX_PAYLOAD_LENGTH in the Android repo (issue #1618).
     public static let maxFramedFileBytes: Int = 10_485_760
 

localPackages/BitFoundation/Tests/BitFoundationTests/BinaryProtocolTests.swift

@@ -354,7 +354,7 @@ struct BinaryProtocolTests {
     func payloadSizeBetweenOldAndNewLimit() throws {
         let payloadSize = 2_000_000
         let payload = Data(repeating: 0x41, count: payloadSize)
-        let packet = TestHelpers.createTestPacket(payload: payload)
+        let packet = TestHelpers.createTestPacket(payload: payload, version: 2)
         
         let encodedData = try #require(BinaryProtocol.encode(packet), "Failed to encode packet")
         let decodedPacket = try #require(BinaryProtocol.decode(encodedData), "Failed to decode packet")

localPackages/BitFoundation/Tests/BitFoundationTests/TestHelpers.swift

@@ -56,7 +56,8 @@ final class TestHelpers {
         recipientID: PeerID? = nil,
         payload: Data = Data("test payload".utf8),
         signature: Data? = nil,
-        ttl: UInt8 = 3
+        ttl: UInt8 = 3,
+        version: UInt8 = 1
     ) -> BitchatPacket {
         return BitchatPacket(
             type: type,
@@ -65,7 +66,8 @@ final class TestHelpers {
             timestamp: UInt64(Date().timeIntervalSince1970 * 1000),
             payload: payload,
             signature: signature,
-            ttl: ttl
+            ttl: ttl,
+            version: version
         )
     }