Initial implementation

Contains JSON hanshake and heartbeat procedure, including rejecting
handshake when no data exposed by connector
Simple loading screen, and then UI opens, no major UI work has been done
yet

test/minimal_connector.py

@@ -0,0 +1,85 @@
+# minimal_connector.py
+from __future__ import annotations
+
+import asyncio
+import uuid
+from dynalab_protocol.models import (
+    ConnectorHello,
+    DynaLabHello,
+    HandshakeAccepted,
+    HandshakeRejected,
+    Heartbeat,
+    SignalDescriptor,
+    machine_timestamp_ms,
+)
+from dynalab_protocol.wire import read_message, write_message
+
+
+HOST = "127.0.0.1"
+PORT = 8765
+
+
+async def main() -> None:
+    reader, writer = await asyncio.open_connection(HOST, PORT)
+
+    dynalab_hello: DynaLabHello
+    handshake: HandshakeAccepted
+
+    peer = writer.get_extra_info("peername")
+    print(f"Connected to DynaLab at {peer}")
+
+    try:
+        message = await asyncio.wait_for(read_message(reader), timeout=5.0)
+
+        if not isinstance(message, DynaLabHello):
+            raise ValueError(f"Expected dynalab_hello, received {message.type}")
+
+        dynalab_hello = message
+        print(f"Received DynaLab Hello\n {dynalab_hello}")
+
+        signals: list[SignalDescriptor] = [
+            SignalDescriptor(
+                id=uuid.uuid4(), name="lambda", type="number", min_value=0, max_value=5
+            )
+        ]
+
+        connector_hello = ConnectorHello(
+            connector_uuid=uuid.uuid4(),
+            connector_name="Minimal Connector",
+            connector_version="a0.0.1",
+            signals=signals,
+        )
+        await write_message(writer, connector_hello)
+
+        message = await asyncio.wait_for(read_message(reader), timeout=5.0)
+
+        if isinstance(message, HandshakeAccepted):
+            handshake = message
+            print(f"Received connection handshake: {handshake}")
+        elif isinstance(message, HandshakeRejected):
+            print(f"Connector handshake rejected: {message.reason}")
+            return
+
+        while True:
+            message = await read_message(reader)
+            print(f"Received {message}")
+
+            if isinstance(message, Heartbeat):
+                if message.sequence < 10:
+                    message.return_timestamp = machine_timestamp_ms()
+                    await write_message(writer, message)
+
+    except asyncio.CancelledError:
+        raise
+
+    finally:
+        print("Disconnecting")
+        writer.close()
+        await writer.wait_closed()
+
+
+if __name__ == "__main__":
+    try:
+        asyncio.run(main())
+    except KeyboardInterrupt:
+        print("\nConnector stopped")