[+!] all but small

some small modifications, tests added

tests/test_entrypoint.py

@@ -0,0 +1,50 @@
+"""Проверка настоящего main.py и TCP.run() в отдельном процессе."""
+
+import asyncio
+from pathlib import Path
+import subprocess
+import sys
+
+
+def test_main_process_handshake_and_heartbeat(client_module, tmp_path):
+    """Запускает main.py на порту ОС из другого cwd, проверяет протокол и завершает процесс."""
+    async def scenario():
+        main = Path(__file__).parents[1] / "src" / "main.py"
+        runner = Path(__file__).with_name("entrypoint_runner.py")
+        process = await asyncio.create_subprocess_exec(
+            sys.executable, "-B", "-u", str(runner), str(main),
+            cwd=tmp_path, stdout=asyncio.subprocess.PIPE, stderr=asyncio.subprocess.PIPE,
+            stdin=asyncio.subprocess.PIPE,
+            creationflags=subprocess.CREATE_NO_WINDOW if sys.platform == "win32" else 0,
+        )
+        client = None
+        try:
+            line = await asyncio.wait_for(process.stdout.readline(), 4)
+            if not line:
+                diagnostic = await asyncio.wait_for(process.stderr.read(), 1)
+                raise AssertionError("main.py не запустил TCP:\n" + diagnostic.decode(errors="replace"))
+            assert line.startswith(b"TCP listening "), line.decode(errors="replace")
+            port = int(line.decode().strip().rsplit(":", 1)[1])
+            assert 0 < port < 65536
+            client = client_module.Client("process-rover", port=port, timeout=2)
+            await client.connect()
+            await client.telemetry()
+            assert await client.heartbeat() == {"command": "heartbeat_answer"}
+        finally:
+            if client is not None:
+                await client.close()
+            if process.returncode is None:
+                try:
+                    process.stdin.write(b"stop\n")
+                    await process.stdin.drain()
+                    process.stdin.close()
+                except (BrokenPipeError, ConnectionResetError):
+                    pass
+            try:
+                stdout, stderr = await asyncio.wait_for(process.communicate(), 4)
+            except TimeoutError:
+                process.kill()
+                stdout, stderr = await process.communicate()
+        assert process.returncode is not None
+        assert process.returncode == 0, stderr.decode(errors="replace")
+    asyncio.run(asyncio.wait_for(scenario(), 12))