_live_e2e_common.py's CONTROLLER_CANDIDATES/XCEADMIN_CANDIDATES only ever
resolved to the three default profile-dir names (xce.build, build.release,
build.dbg), with no way to point the live E2E suite at a binary built to a
custom/explicit build dir. Adds XCE_CONTROLLER_BIN/XCEADMIN_BIN env-var
overrides via a new resolve_binary_candidates() helper -- when set, the
override becomes the sole candidate; otherwise the existing three-name
fallback list is unchanged. Mirrors the ${XCE_CONTROLLER_BIN:-default}
convention already used by clean_failover_preservation.sh/run-ha-soak.sh.
Skip messages in both live E2E test files now mention the override.
TDD: 4 new unit tests in test_live_e2e_common.py (no override, empty
override, override-becomes-sole-candidate, and an end-to-end reload proving
the real module constants respect their env vars). Full xceadmin suite
(288 tests) confirmed unaffected: 287 pass, 1 pre-existing unrelated
failure (a stale redirect-gap assertion, unrelated to this change).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AgYRU3zDTqNGV5Jk8aiKLg
