tests: cover phase 1 commands end to end

Pytest suite with a tiny_client fixture, an ephemeral Ed25519 keypair
fixture, and a threaded HTTPServer helper. Exercises cli dispatch,
inspect (including excluded-path handling), build-manifest and sign
against the real m2dev-client scripts, diff-remote via a local server,
and the full release publish composite against a local rsync target.

tests/fixtures/http_server.py

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+"""Minimal threaded HTTP server for diff-remote / verify-public tests."""
+
+from __future__ import annotations
+
+import contextlib
+import threading
+from http.server import SimpleHTTPRequestHandler, ThreadingHTTPServer
+from pathlib import Path
+from typing import Iterator
+
+
+class _Handler(SimpleHTTPRequestHandler):
+    def log_message(self, format, *args):  # noqa: A002
+        pass  # silence
+
+
+@contextlib.contextmanager
+def serve_dir(root: Path) -> Iterator[str]:
+    """Serve `root` on 127.0.0.1:<free port>, yield the base URL."""
+    handler = lambda *a, **kw: _Handler(*a, directory=str(root), **kw)  # noqa: E731
+    server = ThreadingHTTPServer(("127.0.0.1", 0), handler)
+    thread = threading.Thread(target=server.serve_forever, daemon=True)
+    thread.start()
+    try:
+        yield f"http://127.0.0.1:{server.server_port}"
+    finally:
+        server.shutdown()
+        server.server_close()
+        thread.join(timeout=2)

tests/fixtures/tiny_client/Metin2.exe

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+fake main executable content

tests/fixtures/tiny_client/Metin2Launcher.exe

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+fake launcher content

tests/fixtures/tiny_client/readme.txt

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+tiny client fixture for tests

tests/fixtures/tiny_client/subdir/asset.bin

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+asset payload bytes

tests/fixtures/tiny_client/subdir/other.dat

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+second asset payload