feat(tcp): TCPStreamer DataSources, in-process TCPStreamService, stream multiplexing and TCPStreamJoin

Add TCPStreamer/TCPStreamerClient (TCP transport behind the UDPSServerI/UDPSClientI
seam), an optional single in-process TCPStreamService serving many streams over
worker threads, multiplexed SUBSCRIBE (comma list, stream index in fragmentIdx),
and TCPStreamJoin, which merges several streams into one sample-and-hold stream
paced by a master. StreamHub takes a comma list of streams over one connection.
Includes GTests, E2E scenarios s58-s73 and docs.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Test/E2E/datasources/E2ETCPServiceTest.cfg

@@ -0,0 +1,28 @@
+/**
+ * E2E Test — FileReader → TCPStreamer (in-process TCPStreamService) → TCPStreamerClient → FileWriter
+ * The service is a root object; the streamer joins it with Service/StreamName and the
+ * client subscribes to that stream by name.
+ * Signal names MUST match the binary file header (Signal_100, Signal_1K, Signal_5K).
+ */
++Svc = { Class = TCPStreamService Port = 44622 Workers = 2 }
+$E2ETCPServiceTest = {
+    Class = RealTimeApplication
+    +Functions = {
+        Class = ReferenceContainer
+        +TimerGAM = { Class = IOGAM InputSignals = { Counter = { DataSource = ReaderTimer Type = uint32 } Time = { Frequency = 10 DataSource = ReaderTimer Type = uint32 } } OutputSignals = { Counter = { DataSource = DDB Type = uint32 } Time = { DataSource = DDB Type = uint32 } } }
+        +ReaderGAM = { Class = IOGAM InputSignals = { Signal_100 = { DataSource = FileReaderDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 100 } Signal_1K = { DataSource = FileReaderDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 1000 } Signal_5K = { DataSource = FileReaderDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 5000 } } OutputSignals = { Signal_100 = { DataSource = Streamer Type = float32 NumberOfDimensions = 1 NumberOfElements = 100 } Signal_1K = { DataSource = Streamer Type = float32 NumberOfDimensions = 1 NumberOfElements = 1000 } Signal_5K = { DataSource = Streamer Type = float32 NumberOfDimensions = 1 NumberOfElements = 5000 } } }
+        +ClientGAM = { Class = IOGAM InputSignals = { Signal_100 = { DataSource = ClientDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 100 } Signal_1K = { DataSource = ClientDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 1000 } Signal_5K = { DataSource = ClientDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 5000 } } OutputSignals = { Signal_100 = { DataSource = FileWriterDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 100 } Signal_1K = { DataSource = FileWriterDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 1000 } Signal_5K = { DataSource = FileWriterDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 5000 } } }
+    }
+    +Data = {
+        Class = ReferenceContainer DefaultDataSource = DDB
+        +DDB = { Class = GAMDataSource }
+        +ReaderTimer = { Class = LinuxTimer SleepNature = "Default" Signals = { Counter = { Type = uint32 } Time = { Type = uint32 } } }
+        +FileReaderDS = { Class = FileReader Filename = "/tmp/udpstreamer_test_input.bin" Interpolate = "no" FileFormat = "binary" }
+        +Streamer = { Class = TCPStreamer Service = "Svc" StreamName = "direct" MaxPayloadSize = 65507 PublishingMode = "Strict" Signals = { Signal_100 = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 100 } Signal_1K = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 1000 } Signal_5K = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 5000 } } }
+        +ClientDS = { Class = TCPStreamerClient ServerAddress = "127.0.0.1" Port = 44622 StreamName = "direct" MaxPayloadSize = 65507 Signals = { Signal_100 = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 100 } Signal_1K = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 1000 } Signal_5K = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 5000 } } }
+        +FileWriterDS = { Class = FileWriter NumberOfBuffers = 10 CPUMask = 0x10 StackSize = 10000000 Filename = "/tmp/udpstreamer_test_output_tcpsvc.bin" Overwrite = "yes" StoreOnTrigger = 0 FileFormat = "binary" Signals = { Signal_100 = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 100 } Signal_1K = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 1000 } Signal_5K = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 5000 } } }
+        +Timings = { Class = TimingDataSource }
+    }
+    +States = { Class = ReferenceContainer +Running = { Class = RealTimeState +Threads = { Class = ReferenceContainer +ReaderThread = { Class = RealTimeThread CPUs = 0x1 Functions = {TimerGAM ReaderGAM} } +ClientThread = { Class = RealTimeThread CPUs = 0x2 Functions = {ClientGAM} } } } }
+    +Scheduler = { Class = GAMScheduler TimingDataSource = Timings }
+}

Test/E2E/datasources/E2ETCPTest.cfg

@@ -0,0 +1,25 @@
+/**
+ * E2E Test — FileReader → TCPStreamer → TCPStreamerClient → FileWriter
+ * Signal names MUST match the binary file header (Signal_100, Signal_1K, Signal_5K).
+ */
+$E2ETCPTest = {
+    Class = RealTimeApplication
+    +Functions = {
+        Class = ReferenceContainer
+        +TimerGAM = { Class = IOGAM InputSignals = { Counter = { DataSource = ReaderTimer Type = uint32 } Time = { Frequency = 10 DataSource = ReaderTimer Type = uint32 } } OutputSignals = { Counter = { DataSource = DDB Type = uint32 } Time = { DataSource = DDB Type = uint32 } } }
+        +ReaderGAM = { Class = IOGAM InputSignals = { Signal_100 = { DataSource = FileReaderDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 100 } Signal_1K = { DataSource = FileReaderDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 1000 } Signal_5K = { DataSource = FileReaderDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 5000 } } OutputSignals = { Signal_100 = { DataSource = Streamer Type = float32 NumberOfDimensions = 1 NumberOfElements = 100 } Signal_1K = { DataSource = Streamer Type = float32 NumberOfDimensions = 1 NumberOfElements = 1000 } Signal_5K = { DataSource = Streamer Type = float32 NumberOfDimensions = 1 NumberOfElements = 5000 } } }
+        +ClientGAM = { Class = IOGAM InputSignals = { Signal_100 = { DataSource = ClientDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 100 } Signal_1K = { DataSource = ClientDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 1000 } Signal_5K = { DataSource = ClientDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 5000 } } OutputSignals = { Signal_100 = { DataSource = FileWriterDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 100 } Signal_1K = { DataSource = FileWriterDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 1000 } Signal_5K = { DataSource = FileWriterDS Type = float32 NumberOfDimensions = 1 NumberOfElements = 5000 } } }
+    }
+    +Data = {
+        Class = ReferenceContainer DefaultDataSource = DDB
+        +DDB = { Class = GAMDataSource }
+        +ReaderTimer = { Class = LinuxTimer SleepNature = "Default" Signals = { Counter = { Type = uint32 } Time = { Type = uint32 } } }
+        +FileReaderDS = { Class = FileReader Filename = "/tmp/udpstreamer_test_input.bin" Interpolate = "no" FileFormat = "binary" }
+        +Streamer = { Class = TCPStreamer Port = 44620 MaxPayloadSize = 65507 PublishingMode = "Strict" Signals = { Signal_100 = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 100 } Signal_1K = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 1000 } Signal_5K = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 5000 } } }
+        +ClientDS = { Class = TCPStreamerClient ServerAddress = "127.0.0.1" Port = 44620 MaxPayloadSize = 65507 Signals = { Signal_100 = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 100 } Signal_1K = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 1000 } Signal_5K = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 5000 } } }
+        +FileWriterDS = { Class = FileWriter NumberOfBuffers = 10 CPUMask = 0x10 StackSize = 10000000 Filename = "/tmp/udpstreamer_test_output_tcp.bin" Overwrite = "yes" StoreOnTrigger = 0 FileFormat = "binary" Signals = { Signal_100 = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 100 } Signal_1K = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 1000 } Signal_5K = { Type = float32 NumberOfDimensions = 1 NumberOfElements = 5000 } } }
+        +Timings = { Class = TimingDataSource }
+    }
+    +States = { Class = ReferenceContainer +Running = { Class = RealTimeState +Threads = { Class = ReferenceContainer +ReaderThread = { Class = RealTimeThread CPUs = 0x1 Functions = {TimerGAM ReaderGAM} } +ClientThread = { Class = RealTimeThread CPUs = 0x2 Functions = {ClientGAM} } } } }
+    +Scheduler = { Class = GAMScheduler TimingDataSource = Timings }
+}