Modern power systems with high renewable penetration, electrification, and real-time pricing require synchronized supply- and demand-side flexibility. This work develops a two-stage framework for the joint placement and sizing of dynamic energy storage (DES) and the operational coordination of dynamic demand-side management (DSM) as a multi-objective problem balancing technical performance, a safe operating index (SOI), and a social welfare index (SWI). The SWI represents partial-equilibrium consumer utility net of operating and storage-degradation costs, while the SOI combines normalized steady-state voltage-security headroom and expected energy not served (EENS). An online scheduling layer co-optimizes DES dispatch and DSM modulation through hourly receding-horizon updates under uncertainty. In this work, “dynamic” denotes time-coupled hourly scheduling and state-of-charge evolution rather than electromagnetic, electrochemical, or sub-second transient dynamics. The contribution is formulation-level integration of planning and operation, rather than a new generic optimization algorithm. Reference-case validation on the IEEE 69-bus radial distribution feeder shows improvements over controlled reference-informed benchmark configurations in voltage-security headroom, EENS, feeder losses, peak demand, and welfare. The two-stage formulation separates the mixed-integer planning task from the hourly operational update and provides a transparent basis for Pareto trade-off analysis within the evaluated feeder and assumptions. A separate reconstruction-based robustness assessment uses a fixed 10-scenario ensemble and an IEEE 33-bus execution check to quantify dispersion, parameter sensitivity, and scheduling feasibility without extending the claims beyond the evaluated assumptions.