round-12: fix integration fallout (P9 gate x P1, P7 check x P2/P4 fixtures)

- P1 resident tests: P9's inference gate is a precondition of
  _run_with_vm, so _RealExecCase.make_executor now configures a
  default inference origin (CHV_INFERENCE_ORIGIN=https://xgapi.lol
  + CHV_INFERENCE_ALLOW_HOSTS=xgapi.lol) and a public fake resolver
  (same setup as P9's GateTest). No assertion changed; the gate's
  fail-closed behavior on missing origin stays pinned by P9's own
  ask test. 9 resident tests fixed (7 errors + 2 failures).
- P2/P4 dry-run fixtures: P7's build.sh hard check requires
  chv-memory.py in the repo; add it to both fixtures' copy lists.
  2 failures fixed.
- No production code changed in this commit (test setup only).

cloud/tests/test_chv_muse_p2.py

@@ -552,7 +552,7 @@ class BuildDryRunTest(unittest.TestCase):
                          "authd.py", "git-credential-chv-authd",
                          "chv-authd.service",
                          "chv-cdp-broker.py", "chv_browser_guard.py",
-                         "browser-blocklist.txt"):
+                         "browser-blocklist.txt", "chv-memory.py"):
                 shutil.copy2(ROOT / "chv-guest" / name,
                              os.path.join(guest, name))
             shutil.copy2(ROOT / "host.py", os.path.join(repo, "host.py"))