{
  "task_id": "DEV-000172",
  "task_revision": 1,
  "architecture_revision": "ADR-0018",
  "base_repo_revision": "2c7a85779b530e3147fbf47b71742759cc010d58",
  "risk_tier": "E",
  "intent": "Make fleet failover choose the best available non-Lifeboat tier below the preferred tier before using Lifeboat.",
  "requirement_ids": ["WP-301", "Model fleet/failover"],
  "allowed_change_scope": {"modules": ["capability", "cognitive-worker"], "paths": ["modules/capability/domain/fleet.go", "modules/capability/domain/fleet_test.go", "cmd/cognitive-worker/fleet_status_test.go", "dev/ACTIVE_TASK.json", "dev/tasks/DEV-000172-fleet-failover-priority.json"]},
  "forbidden_change_scope": {"paths": ["architecture/**", "security/**", "database/**", "deploy/**", "contracts/**", "adapters/**", ".gitea/**"]},
  "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 FleetReadiness contract", "existing FleetTier selection contract"], "may_change": []},
  "semantic_owner": "capability",
  "canonical_state": [],
  "state_transitions": ["preferred unavailable -> next lower ready tier -> Lifeboat fallback"],
  "side_effects_and_privileges": ["none"],
  "persistence_and_migrations": ["none"],
  "failure_retry_restart": ["selection remains deterministic from observed readiness; invalid preferred tier fails closed"],
  "assumptions": ["HEAVY > MEDIUM > FAST is the quality/capability fallback order; LIFEBOAT is last-resort recovery"],
  "acceptance_scenarios": ["HEAVY unavailable and MEDIUM ready selects MEDIUM", "HEAVY and MEDIUM unavailable and FAST ready selects FAST", "all primary tiers unavailable selects Lifeboat", "invalid preferred tier is rejected"],
  "required_tests": ["go test ./...", "go vet ./...", "preflight", "check-diff", "check-architecture", "independent", "git diff --check", "CI", "production fleet readiness"],
  "terminal_gap_states": ["BLOCKED_BY_MISSING_CAPABILITY", "BLOCKED_BY_CONFLICT"]
}