feat(resource-value-verification): apiserver-side verification check (task 6.4)

poll_apiserver_log()/query_apiserver_resvals() mirror task 6.3's
scheduler-check pattern: bounded-wait polling (batched across all pending
resources per iteration) of apiserver.log for task 4.2's "resource-location
stored" trace line, parsing the trailing zap JSON block. Reports MATCH /
MISMATCH (both values) / UNREACHABLE (timeout, distinct from mismatch),
tracked in APISERVER_OBSERVED/APISERVER_CHECK_RESULTS +
apiserver-check-results.tsv.

This completes all three per-layer checks. Live-confirmed: the full default
resource set (including cpuf, post-bug-1579-fix) MATCHes simultaneously at
the controller, scheduler, and apiserver layers.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.kiro/specs/resource-value-verification/tasks.md

@@ -84,7 +84,7 @@
   - _Depends: 6.1, 6.2_
   - _Boundary: xce-test-resources skill (scheduler check) — same file as 6.2/6.4, sequential_
 
-- [ ] 6.4 Implement the apiserver-side verification check via trace-log tail
+- [x] 6.4 Implement the apiserver-side verification check via trace-log tail
   - Tail/grep the live apiserver's log file (task 4.2's trace line) for each injected resource/worker pair, polling with a short interval up to a generous, explicit bounded wait — no `xcecli` query, no REST call
   - Compare the apiserver's observed value against the injected value, reported distinctly from the controller-side and scheduler-side results; a timeout with no matching line is reported as "unreachable," distinct from a value mismatch
   - Observable completion: the check reports, per resource, whether the apiserver's observed value matches the injected value within the bounded wait, attributable specifically to the apiserver layer
@@ -116,6 +116,7 @@
   - _Depends: 7.1_
 
 ## Implementation Notes
+- Task 6.4: `poll_apiserver_log()`/`query_apiserver_resvals()` mirror task 6.3's scheduler-check pattern exactly (same bounded-wait/batched-polling shape). The apiserver's zap `console` encoder renders structured fields as a trailing JSON object (`resource-location stored {"resource": "r15m", "host": "...", "value": 1.5}`), not classic `key=value` text — grep for the message string, then parse the trailing JSON block. All three layers (controller/scheduler/apiserver) confirmed simultaneously MATCH on the full default set including `cpuf`, proving the bug-1579 fix holds end-to-end.
 - **bug-1579 is now FULLY fixed** (retrofit on top of tasks 6.1/6.2, not a numbered task — user-requested follow-up). `inject_resources()`'s worker-context `xce_test` script now inserts a `!<shell-command>` line between `resupdate` and `quit`: `! bash <script> --internal-controller-check <top> <peers> <worker-host> <names...>` — this runs the controller-check query via `xce_test`'s `!` shell-escape (`preprocess_and_run()`, handled in the single top-level REPL loop before context dispatch, so it works in ANY context including `worker` mode without disconnecting). The controller check now runs WHILE the injecting worker's connection is still open, so host-attrs resources are never reset before being checked. `DEFAULT_RESOURCE_ARGS` now includes `cpuf` again (proof the fix works: `cpuf` now MATCHes at the controller layer, not the old false MISMATCH). `query_controller_resvals()`'s comparison logic (`controller_values_match()`) is confirmed byte-for-byte unchanged — this was a pure sequencing fix. Any future task touching `inject_resources()`/the controller-check flow should be aware of this nested-process structure (`--internal-controller-check` is a hidden internal dispatch flag, gated before `main()`/`parse_args()` runs — do not remove it thinking it's dead code).
 - Non-blocking notes from the retrofit's review: `internal_controller_check()` queries ALL requested resource names (including ones that will later be rejected), not just accepted ones like the original design — forced by sequencing (accept/reject isn't known until the whole injecting session's output is parsed after it returns); confirmed benign, the final `controller-check-results.tsv` still correctly omits rejected names. Also: invoking `--internal-controller-check` directly with fewer than 3 args hits `set -u` and dies with a raw "unbound variable" message instead of a clean `fail()` — cosmetic only, this path is unreachable from any normal invocation.
 - Minor non-blocking follow-up from task 6.3's review: `poll_scheduler_log()`'s output isn't filtered to the caller's `pending` list (harmless today since the only caller already filters, but worth tightening).