feat(scheduler-sim-decision-parity): reconstruct job allocation with safe ownership (task 2.3)

Extends sim_reconcile_unaccounted_jobs()'s FOUND branch: takes ownership of
a matched recorded DISPATCH decision's allocation (job->allocs = entry's
alloc, not a copy -- mirrors scheduler.c's sched_commit_decision()
precedent exactly), builds job->accounts via make_job_account(), then
safely consumes the recorded entry -- nulling the source alloc pointer
BEFORE freeing the entry (preventing a double-free through job->allocs),
then compacting decoded_session->decisions via shift-down (memmove, never
swap-with-last, which would reorder the remaining entries and break the
positional --sim-verify comparison a later task depends on).

Fixed a real correctness bug found while implementing: the "not found"
check (i == n_decisions) goes stale once n_decisions can be decremented
mid-loop by compaction -- replaced with an explicit found flag.

Primary correctness bar: reconcile-then-release-through-normal-job-cleanup
is ASAN-clean. Verified with ASAN_OPTIONS=detect_leaks=1 (beyond this
suite's registered detect_leaks=0): zero double-free/UAF/overflow. Found
and logged (not fixed, out of boundary) a real pre-existing leak in
src/lib/misc.c's free_host_account() -- equally present on the live
dispatch path, bug-1621.

46/47 scheduler tests pass; the 1 failure is pre-existing bug-1560
(unrelated).

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

.kiro/specs/scheduler-sim-decision-parity/tasks.md

@@ -36,7 +36,7 @@
   - _Requirements: 4.1, 4.2_
   - _Boundary: Recorded-Decision Reconciliation_
 
-- [ ] 2.3 Reconstruct an already-resolved job's allocation from its recorded decision, safely
+- [x] 2.3 Reconstruct an already-resolved job's allocation from its recorded decision, safely
   - When a matching recorded dispatch decision is found (task 2.2), take ownership of its resource-allocation data to become the job's own allocation and accounting record — the same ownership-transfer pattern the live dispatch path already uses, not a duplicate copy
   - Once that data has been taken over, remove the now-fully-consumed recorded decision entry from this round's decoded data, releasing only the parts of it that were not taken over, and close the resulting gap so the remaining recorded entries keep their original relative order
   - A job whose allocation is reconstructed this way must never be reconsidered by this same mechanism again on a later round
@@ -91,3 +91,6 @@
 - (task 1.2) Whole-scenario white-box test files in `src/scheduler/testsuite/` (fixture construction + real driver/allocator plumbing) routinely exceed the project's 800-line guidance (`test_sim_verify.c` is 934 lines, uncorrected; the new `test_sim_resource_contention.c` is 883) — the steering's "don't use as precedent" caveat names only non-test files, so this is an accepted pattern for this class of test, not a defect to fix per task. Tasks 4.1-4.3 will likely add similarly-sized files; don't flag file size alone as blocking for them.
 - (task 2.1) Confirmed (by reading `sim_picker_thread_fn()`): simulation mode's live picker thread unconditionally PENDs every job today, and `sched_commit_decision()` (the only real setter of `job->accounts`) is normal-mode-only. So after 2.1 alone, `resInUse` is still zero end-to-end in sim mode -- 2.1 only wires the call site/interleaving slot. Tasks 2.2-2.4 (Recorded-Decision Reconciliation) are what actually populate `job->accounts` and make `resInUse` correct. Don't expect nonzero `resInUse` from a sim run until 2.2-2.4 land -- this is expected, not a regression.
 - (task 2.1) White-box test files that `#include "../src/sim_loop.c"` directly (test_sim_event_loop.c, test_sim_verify.c, test_sim_alt_events.c, test_sim_record_output.c, test_repl_breakpoints_inspection.c, test_repl_snapshot_params.c, test_repl_execution_control.c, test_repl_equivalence.c) need a link-satisfying stub added whenever sim_loop.c gains a new extern reference (here: `sched_account_jobs()`). Tasks 2.2-2.4 will likely add more such references (e.g. into the recorded-decision/reporting machinery) -- expect to touch these same 8 files again for stub updates, and check for linker errors rather than guessing which files need it.
+- (task 2.3) Do NOT check "not found" via `i == decoded_session->n_decisions` after the lookup loop once the loop's array can be mutated mid-iteration (e.g. once `n_decisions` gets decremented by a compaction) -- that check goes stale for a last-index match. Use an explicit `found` flag instead. This bug would only have surfaced later (task 2.3 introduced the mutation that makes the old check wrong) but was caught and fixed here.
+- (task 2.3) `src/lib/misc.c`'s `free_host_account()` never frees the `strdup`'d `host` field `make_host_account()` (`src/lib/xcealloc.c:119`) allocates -- a real, pre-existing leak, equally present on the live `scheduler.c` dispatch/release path, previously masked because this test suite is registered with `ASAN_OPTIONS=detect_leaks=0`. Logged as bug-1621, intentionally NOT fixed here (out of this feature's boundary -- misc.c isn't owned by scheduler-sim-decision-parity). If a later task's ASAN run surfaces this same leak, it's not a new regression -- don't waste time re-diagnosing it, it's bug-1621.
+- (task 2.3) `make_job_account()`'s return isn't NULL-checked before use, matching the live-path precedent (`scheduler.c`'s `sched_commit_decision()` has the same gap) -- informational only, not a defect to fix in this feature unless the live path itself gets hardened first.