fix(issue-45): the shim bootstrap starts MAM servers with restore-on-restart off

The headless bootstrap regenerates the server config on every start and hands
it to the server as HERDR_CONFIG_PATH. Without a file the server still starts,
with a warning. mam_sandbox unsets HERDR_CONFIG_PATH/XDG_CONFIG_HOME so the
file lands in the sandbox HOME.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_issue9_server_env.py

@@ -150,6 +150,27 @@ def test_bootstrap_strips_agent_runtime_markers(mam_sandbox):
         assert key in server_env
 
 
+def test_bootstrap_hands_the_server_a_no_restore_config(mam_sandbox):
+    """Issue #45: the server starts with HERDR_CONFIG_PATH = the user's herdr
+    config plus [session] resume_agents_on_restore = false (that herdr obeys it
+    is test_issue45_restore.py, on a real server)."""
+    import tomllib
+    env = _install_fake_herdr(mam_sandbox)
+    user_cfg = mam_sandbox / ".config" / "herdr" / "config.toml"
+    user_cfg.parent.mkdir(parents=True)
+    user_cfg.write_text("[ui]\nconfirm_close = false\n")
+
+    res = _run_through_shim(mam_sandbox, env, "issue45-probe")
+    assert res.returncode == 0, res.stderr
+    assert "restore-on-restart stays enabled" not in res.stderr, res.stderr
+
+    server_env = json.loads(Path(env["FAKE_HERDR_ENV_DUMP"]).read_text())
+    assert server_env.get("HERDR_CONFIG_PATH") == str(user_cfg.parent / "mam-server-config.toml")
+    assert "MAM_SERVER_CFG" not in server_env
+    cfg = tomllib.loads(Path(server_env["HERDR_CONFIG_PATH"]).read_text())
+    assert cfg == {"ui": {"confirm_close": False}, "session": {"resume_agents_on_restore": False}}
+
+
 def test_no_autostart_skips_bootstrap_but_still_routes_the_call(mam_sandbox):
     env = _install_fake_herdr(mam_sandbox)
     env["MAM_NO_AUTOSTART"] = "1"