feat(work): require verified graph result fan-in

dev/ACTIVE_TASK.json

@@ -1,5 +1,5 @@
 {
-  "task_file": "dev/tasks/DEV-000232-durable-solution-wave-dispatch.json",
-  "task_id": "DEV-000232",
+  "task_file": "dev/tasks/DEV-000233-graph-result-fanin-verification.json",
+  "task_id": "DEV-000233",
   "task_revision": 1
 }

dev/tasks/DEV-000233-graph-result-fanin-verification.json

@@ -0,0 +1,23 @@
+{
+  "task_id": "DEV-000233",
+  "task_revision": 1,
+  "architecture_revision": "ADR-0018",
+  "base_repo_revision": "ee16103e03a5fd911119e2bc45e5904255ab7752",
+  "risk_tier": "E",
+  "intent": "Close the multi-agent Work Graph result lifecycle: persist attributable agent candidates, prevent candidate text from completing a node, and complete only after independently verified synthesis.",
+  "requirement_ids": ["fan-in", "independent verifier", "result provenance", "no false completion"],
+  "allowed_change_scope": {"modules": ["work-graph", "agent-execution", "postgres-work-adapter"], "paths": ["contracts/work/graph.go", "modules/work/ports/graph.go", "modules/work/application/graph_runtime.go", "adapters/postgres/work_repository.go", "cmd/work-graph-runtime/main.go", "tests/agent_execution/graph_runtime_test.go", "dev/ACTIVE_TASK.json", "dev/tasks/DEV-000233-graph-result-fanin-verification.json", "docs/PROJECT_STATUS.md"]},
+  "forbidden_change_scope": {"paths": ["architecture/**", "security/**", "database/**", "deploy/**", "LLM-local/**", "modules/work/secrets/**"]},
+  "allowed_architecture_delta": {"new_cross_module_dependencies": 0, "new_canonical_owners": 0, "new_privileges": 0, "new_third_party_dependencies": 0, "new_database_owner_roles": 0},
+  "contracts": {"consume": ["existing Work Graph revision store", "existing graph result candidate/synthesis tables", "agent callback evidence"], "may_change": ["typed graph result callback", "Work result callback route", "verified synthesis completion path"]},
+  "semantic_owner": "Work Graph result and verification lifecycle",
+  "canonical_state": ["work.graphs, work.graph_nodes, work.graph_result_candidates, work.graph_conflicts and work.graph_synthesis_candidates"],
+  "state_transitions": ["agent result -> durable ResultCandidate", "candidate -> no completion", "independent verified synthesis -> graph node SUCCEEDED", "all verified nodes -> graph COMPLETED"],
+  "side_effects_and_privileges": ["Work-owned candidate/graph persistence only; no provider call, secret access, external mutation, promotion or deployment"],
+  "persistence_and_migrations": ["none; existing result candidate and synthesis tables are reused"],
+  "failure_retry_restart": ["immutable graph revisions remain attributable; duplicate candidate IDs are idempotent at storage; missing or unverified synthesis cannot mark success"],
+  "assumptions": ["the verifier supplies all competing candidates and evidence in the synthesis request", "automatic replan selection remains the next stage because a graph does not yet own a persisted goal-search snapshot"],
+  "acceptance_scenarios": ["result callback persists candidate", "result callback leaves graph running and not completed", "verified independent synthesis advances the node", "verifier cannot be a producer", "fan-in completion requires all graph nodes successful"],
+  "required_tests": ["go test ./modules/work/domain ./modules/work/application ./tests/agent_execution ./cmd/work-graph-runtime/...", "go vet ./modules/work/domain ./modules/work/application ./tests/agent_execution ./cmd/work-graph-runtime/...", "preflight", "check-diff", "check-architecture", "independent", "git diff --check", "CI", "production health smoke"],
+  "terminal_gap_states": ["BLOCKED_BY_MISSING_CAPABILITY", "BLOCKED_BY_SPEC_GAP"]
+}