Accumulate observations once per structural path instead of allocating and serializing a path for every payload value. Remove the CDP body-shape wrapper and retain primitive, empty-array, and literal-property semantics.
Validation: CDP capture/comparison regressions and CLI/MCP boundary checks pass; 1,507 differential cases match the previous implementation. A 2.5 MB repeated-row workload improves from 105.0 ms to 14.6 ms warm median across alternating runs. Real browser providers were not exercised.