fix: disable agent dry-run without executor

dev/ACTIVE_TASK.json

@@ -1,5 +1,5 @@
 {
-  "task_file": "dev/tasks/DEV-000147-model-fleet-operations-ui.json",
-  "task_id": "DEV-000147",
+  "task_file": "dev/tasks/DEV-000148-agent-worker-no-dry-run.json",
+  "task_id": "DEV-000148",
   "task_revision": 1
 }

dev/tasks/DEV-000148-agent-worker-no-dry-run.json

@@ -0,0 +1,23 @@
+{
+  "task_id": "DEV-000148",
+  "task_revision": 1,
+  "architecture_revision": "ADR-0018",
+  "base_repo_revision": "7030a51b69a4d7345c5475d2fcced0e6d0441916",
+  "risk_tier": "E",
+  "intent": "Prevent agent-worker from claiming or completing dispatches without a configured real executor while preserving durable stale-lease recovery.",
+  "requirement_ids": ["WP-301", "WP-302", "INV-AUTH-001", "INV-CONT-001"],
+  "allowed_change_scope": {"modules": ["work", "agent-worker"], "paths": ["cmd/agent-worker/main.go", "modules/work/application/worker.go", "modules/work/application/worker_test.go", "dev/ACTIVE_TASK.json", "dev/tasks/DEV-000148-agent-worker-no-dry-run.json"]},
+  "forbidden_change_scope": {"paths": ["architecture/**", "security/**", ".gitea/**", "database/**", "contracts/**", "adapters/**", "deploy/**"]},
+  "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": ["WorkerStore", "AgentExecutor"], "may_change": []},
+  "semantic_owner": "work",
+  "canonical_state": ["dispatch queue claims and stale lease recovery"],
+  "state_transitions": ["executor absent -> recovery-only; no new dispatch claim"],
+  "side_effects_and_privileges": ["work-owner stale claim recovery only when executor is absent"],
+  "persistence_and_migrations": [],
+  "failure_retry_restart": ["worker remains restartable and resumes recovery-only mode until bridge is configured"],
+  "assumptions": ["AGENT_EXECUTION_BRIDGE_URL is the only production activation path for external execution"],
+  "acceptance_scenarios": ["missing bridge never claims a queued dispatch", "missing bridge never marks work completed", "stale claims are still recovered", "configured bridge path remains unchanged"],
+  "required_tests": ["go test ./...", "go vet ./...", "preflight", "check-diff", "check-architecture", "independent", "git diff --check"],
+  "terminal_gap_states": ["BLOCKED_BY_MISSING_CAPABILITY", "BLOCKED_BY_CONFLICT"]
+}