Port install_rvs to the orch fixture + Tier-1 dispatch tests

[atnair-amd]

Summary

• Migrate cvs/tests/health/install/install_rvs.py from the legacy phdl/shdl Pssh handles to the shared orch fixture (cvs/tests/conftest.py), mirroring rvs_cvs.py. 21 call sites become orch.exec.
• Drop the dead config_dict['nfs_install'] is True head-only dispatch (the JSON value is the string "True" in the canonical config, is True was always false, so head-only mode was never engaged in shipped configs).
• Add Tier-1 dispatch unit tests covering both BaremetalOrchestrator and ContainerOrchestrator (cvs/tests/health/install/unittests/test_install_rvs_dispatch.py).

Commits

1. eb43701 — Port install_rvs to the orch fixture; update orchestrator scope docs (5 files, +34 / -91).
2. cf34cbf — Add Tier-1 dispatch tests for install_rvs orch port (2 files, +134).

Test plan

Tier-1 — mocked dispatch tests (devbox)

python -m unittest cvs.tests.health.install.unittests.test_install_rvs_dispatch -v:

test_dispatches_via_orch_exec_only (TestInstallRvsBaremetalDispatch) ... ok
test_dispatches_via_orch_exec_only (TestInstallRvsContainerDispatch) ... ok
----------------------------------------------------------------------
Ran 2 tests in 0.003s
OK

Tier-1 proof of detection (mutate-revert per incremental-pr-work.mdc §2)

M1 — change install_rvs.py:217 orch.exec('which rvs', timeout=30) → orch.exec_on_head('which rvs', timeout=30). Both tests FAIL:

AssertionError: mock('which rvs', timeout=30) call not found

Revert → 2 PASS.

M2 — change install_rvs.py:217 timeout=30 → timeout=99. Both tests FAIL on the same assertion (actual call shows timeout=99). Revert → 2 PASS.

Tier-2 — real cluster (single MI300X node 10.245.128.47 / a06u43, ROCm 7.2.0, RVS pre-installed)

Baremetal orchestrator:

PYTHONPATH=/data/atnair/repos/cvs-install-rvs-port \
  ~/repos/cvs/.cvs_venv/bin/cvs run install_rvs \
  --cluster_file=/tmp/cvs_install_rvs_aimvt/cluster_baremetal.json \
  --config_file=/tmp/cvs_install_rvs_aimvt/mi300_health_config.json
# 1 passed in 20.30s
# "RVS installation and verification completed successfully"

Container orchestrator (cvs-harness/rocm-dev:rvs-installed):

PYTHONPATH=/data/atnair/repos/cvs-install-rvs-port \
  ~/repos/cvs/.cvs_venv/bin/cvs run install_rvs \
  --cluster_file=/tmp/cvs_install_rvs_aimvt/cluster_container.json \
  --config_file=/tmp/cvs_install_rvs_aimvt/mi300_health_config.json
# 1 passed in 6.03s
# Container launched: atnair_install_rvs_aimvt
# Commands routed via: sudo docker exec atnair_install_rvs_aimvt ...
# Container torn down: sudo docker rm -f atnair_install_rvs_aimvt

PYTHONPATH=... is the devbox-local workaround for the editable install in ~/repos/cvs/.cvs_venv/ pointing at the main cvs repo rather than this worktree; it ensures the cvs CLI loads the ported install_rvs.py.

Notes

• The first commit's body mentions container Tier-2 was blocked by MultiProcessPssh.exec dropping the detailed= kwarg. That bug was fixed independently in Add upload_file and download_file support #161 (commit d666287, "Add upload_file and download_file support"), which now sits between this branch's base and HEAD. The branch was rebased onto current main to pick it up; container Tier-2 has since been exercised end-to-end and passes (see above).
• The nfs_install head-only branch was deliberately dropped. On the canonical mi300_health_config.json, JSON had "nfs_install": "True" (a string) and the test compared with is True, so head-only was never engaged. Hand-rolled configs that relied on JSON boolean true will install on all nodes in parallel instead of just the head node; this matches what cvs run install_rvs already did via parallel SSH in shipped configs.

Out of scope / Future additions

• Tier-2 cluster verification with the nfs_install pre/post matrix (8 stdout diffs across baremetal/container × nfs_install=true/false × pre/post) — covered in the orch_refactor-suite-install-rvs-test.md plan; queued as a separate PR.
• Tier-1 dispatch tests for install_transferbench / install_agfhc / install_rocblas / install_babelstream — queued per-suite as those migrations land.