feat(executor): add DAG auto-cascade-fail + role-typed subtask spawning (Phase 6)

2026-07-03T23:22:42+00:00

Two prerequisites for safe parallel evaluator fan-out (later phase): 1. Auto-cascade-fail: previously, a failed task's dependents just sat PENDING/QUEUED forever (or until something eventually tried to dispatch them and discovered the dependency was dead). Pool.cascadeFail now fires right after a task lands in a terminal failure state (FAILED/TIMED_OUT/ CANCELLED/BUDGET_EXCEEDED, from handleRunResult, the budget-gate reject path, and the checkDepsReady dependency-failure path), recursively cancelling every not-yet-run dependent (PENDING/QUEUED only -- RUNNING and terminal states are left alone) with a message referencing the upstream failure. A visited-set guards recursion, which turned out to be load-bearing rather than defense-in-depth: task creation does not prevent dependency cycles anywhere in this codebase. Correction to an earlier assumption: internal/executor's waitForDependencies is dead code, never called. The live mechanism is checkDepsReady, invoked synchronously in execute() with a self-requeue via time.AfterFunc. Added a freshness re-check (GetTask, bail if no longer QUEUED) at the top of that block so a task cascade-cancelled while sitting in the requeue loop stops silently instead of hitting an invalid CANCELLED->CANCELLED transition or, worse, still getting dispatched. 2. storeChannel.SpawnSubtask hardcoded Agent.Type: "claude" on every spawned child regardless of what role it should play -- a hard blocker for a Planner/Builder task spawning role-typed evaluator subtasks. SubtaskSpec (internal/agentchannel) gains a Role field; when set, the child task gets Agent.Role instead of a hardcoded Type, so Phase 5's role-resolution picks provider/model from that role's escalation ladder. spec.Role == "" (every existing caller) preserves today's exact behavior byte-for-byte -- proven by an explicit regression test, not just new-feature coverage. Threaded the new `role` parameter through both spawn_subtask transports: the native tool-use loop (internal/agentloop/tools.go) and the MCP tool exposed to ContainerRunner-driven claude/gemini agents (internal/executor/agentmcp.go). go build/vet/test -race -count=1 all pass, full suite (20 packages). Co-Authored-By: Claude Sonnet 5 Claude-Session: https://claude.ai/code/session_01V1moSNCJRcP6kykA4tyUSs

claudomator.git/internal/executor/cascade_test.go, branch fix/dockersandbox-gitpush-host-security

feat(executor): add DAG auto-cascade-fail + role-typed subtask spawning (Phase 6)