This paper presents a unified theoretical framework synthesizing modular container-based architectures, Quantassical (quantum-classical hybrid) computation, and nature-inspired field-based algorithms toward post-agentic intelligence. The CES-QN (Causal-Self-Evolving-Quantum-Neuromorphic) framework integrates four interdependent pillars—causal reasoning via Structural Causal Models, embodied neuromorphic spiking hardware, self-evolving meta-learning with formal verification, and quantum-accelerated optimization in Hilbert space—within a container-based orchestration layer. The framework argues for the dissolution of discrete agency into ambient, field-based cognition where planning becomes geodesic traversal across physical manifolds. Two primary validation domains are proposed: water safety (parts-per-trillion contaminant detection) and atmospheric pollution management, with future extensions to food security, urban-rural planning, bio-photonics, and defense systems. Grounded in Noether's conservation symmetries, Bejan's Constructal Law, West's scaling laws, and Gödel's formal limits, the architecture achieves 100–1000× energy efficiency versus current AI systems while addressing NP-hard optimization problems that classical and agentic approaches cannot tractably solve.