fix: bound task failures and release stalled workers

artemis/runtime/task_limits.py

@@ -0,0 +1,30 @@
+"""Execution budgets shared by supervised web and MCP tasks."""
+
+from dataclasses import dataclass, field
+import time
+
+from artemis.config.settings import settings
+
+
+def task_timeout(item: dict, job: dict | None = None, batch: dict | None = None) -> int:
+    options = item.get("runtime_overrides") or (job or {}).get("case", {}).get("task_config") or {}
+    return int(
+        options.get("timeout_seconds")
+        or (batch or {}).get("timeout_seconds")
+        or settings.ARTEMIS_TASK_TIMEOUT_SECONDS
+    )
+
+
+@dataclass
+class ExecutionBudget:
+    limit: float
+    elapsed: float = 0
+    _last: float = field(default_factory=time.monotonic)
+    _excluded: bool = False
+
+    def update(self, *, excluded: bool = False) -> float:
+        now = time.monotonic()
+        if not self._excluded:
+            self.elapsed += max(0, now - self._last)
+        self._last, self._excluded = now, excluded
+        return max(0, self.limit - self.elapsed)