Add Neural Flow Maps paper summary

[cursor]

Adds the Agent 1 summary for “Fluid Simulation on Neural Flow Maps” (arXiv:2312.14635).

• Uses valid flow-maps, implicit-representations, and world-simulation tags
• Documents the paper’s problem, NFM/SSNF solution, core concepts, and central equations
• Selects Figures 2, 4, and 19 as method-focused extract visuals
• Excludes result, benchmark, ablation, and dataset/example figures

Validation: JSON syntax and PaperSummary schema validation passed. Rendering and publishing were intentionally not run.