search-with-proof group 4 + image: board, spend reservation, coordinator, search-task image

Board as immutable versioned blobs (coordinator sole writer); budget reserve/settle
before model calls; per-task and run caps; coordinator loop over an injected
executor; batch.py accepts a fixed allow-list of search variables; XSS browser
oracle; ousast-search-task image (Python, Node/TypeScript, PHP, Java 17, sqlite,
bwrap, chromium) built by CI. 103 tests on the host.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

tests/test_search_budget.py

@@ -0,0 +1,58 @@
+from concurrent.futures import ThreadPoolExecutor
+
+import pytest
+
+from openultrasast.plane.budget import BudgetExhausted, SpendBudget
+from openultrasast.search.budget import SearchBudget
+
+
+def test_reserve_settle_release():
+    meter = SpendBudget(1)
+    reservation = meter.reserve(0.7)
+    with pytest.raises(BudgetExhausted):
+        meter.reserve(0.4)
+    reservation.settle(0.2)
+    assert meter.spent == 0.2 and meter.reserved == 0
+    other = meter.reserve(0.8)
+    other.release()
+    assert meter.reserved == 0
+    with pytest.raises(ValueError):
+        reservation.settle(0.1)
+    for bad in [-1, float("nan"), float("inf")]:
+        with pytest.raises(ValueError):
+            meter.reserve(bad)
+
+
+def test_concurrent_reservations_cannot_overrun():
+    meter = SpendBudget(1)
+
+    def reserve(_):
+        try:
+            return meter.reserve(0.3)
+        except BudgetExhausted:
+            return None
+
+    with ThreadPoolExecutor(max_workers=12) as pool:
+        reservations = list(pool.map(reserve, range(20)))
+    assert sum(r is not None for r in reservations) == 3
+    assert meter.reserved <= 1
+
+
+def test_config_validation():
+    assert SearchBudget().task_wall_seconds == 900
+    for kwargs in [dict(retries=-1), dict(memory_bytes=0), dict(wall_seconds=float("nan"))]:
+        with pytest.raises(ValueError):
+            SearchBudget(**kwargs)
+
+
+def test_settlement_bound_and_release_then_readmission():
+    meter = SpendBudget(0.5)
+    reserved = meter.reserve(0.5)
+    with pytest.raises(ValueError, match="exceeds reservation"):
+        reserved.settle(0.6)
+    assert meter.reserved == 0.5 and meter.spent == 0
+    reserved.release()
+    meter.reserve(0.5).settle(0.5)
+    assert meter.spent == 0.5
+    with pytest.raises(BudgetExhausted):
+        meter.reserve(0.001)