test(xce-test-rc-file): task 3.3 confirm existing automation unaffected

No product/spec-test code changed. Ran the real xce-test-ha soak and
xce-test-resources verification drivers with no rc file present anywhere
in the environment they run under -- both pass their own documented
success criteria unchanged (zero job loss across rolling failover; zero
resource-value mismatches across controller/scheduler/apiserver), proving
Requirement 1.3's "no rc file -> unchanged behavior" guarantee holds for
real, pre-existing automation that has no awareness this feature exists.

Marks all tasks in the xce-test-rc-file spec complete.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AgYRU3zDTqNGV5Jk8aiKLg

.kiro/specs/xce-test-rc-file/tasks.md

@@ -47,7 +47,7 @@
   - _Requirements: 3.1, 3.2, 3.3, 3.4_
   - _Depends: 2.2_
 
-- [ ] 3.3 Confirm existing xce_test automation is unaffected when no rc file is present
+- [x] 3.3 Confirm existing xce_test automation is unaffected when no rc file is present
   - Run the existing HA soak and resource-verification scripts (the known live callers of xce_test today) in an environment with no rc file at the resolved location
   - Compare their pass/fail result against their pre-feature baseline behavior
   - Observable: the existing scripts' outcomes are unchanged, demonstrating this feature introduces no regression for callers that know nothing about it
@@ -61,3 +61,4 @@
 - Task 1.2: `fopen()` succeeds on a directory path on this platform's glibc — the EISDIR failure only surfaces on the first `getline()` call (`errno=EISDIR`, `ferror(f)` set). A naive `if (!f)` open-failure check misses this; a post-loop `ferror(f)` check is required to catch it (see `rcfile_load()`, bug-1716).
 - Task 1.2: an ASAN heap-use-after-free was observed ONCE in an ad-hoc standalone `controller_unit_test` run (`commit_resolve_pending`/`fsync_worker`/`tap_teardown` in `test_apply_pump.c`) — did not reproduce on a second run or in the canonical `xce-build.sh` run. Unrelated to this spec's files; logged as bug-1717 (unreproduced flake) for tracking. If it recurs on a later task's run, capture the full ASAN report before assuming it's this spec's fault.
 - Task 3.1: `test_rcfile_integration.sh`'s per-test scratch `$HOME` dirs are cleaned via explicit `rm -rf` in each test function's normal flow, but there's no script-level `trap ... EXIT INT TERM` (unlike `clean_failover_preservation.sh`'s global trap) — an interrupted run could leak a small scratch dir. Verified low-impact (small footprint, no leak in normal runs) but worth adding a trap if this script is extended later.
+- Task 3.3: `xce-build.sh <component>` without `--incremental` wipes the whole build dir before rebuilding only that one component (documented bug-1565 behavior) — running it for a component other than `controller` after a controller build silently deletes `xce_controller`/`xce_test`. Use `--incremental` (or `all`) when you need multiple binaries from the same build dir alongside each other.