Replace raw ps[N] access across all CUDA kernels with PS_* named
constants defined in state_layout.cuh. 32 constants total covering
the full 38-slot portfolio state: position/cash/value, DSR stats,
Kelly stats, plan fields, and OFI scratch range.
Notable deviations from pre-written plan mapping: the plan's
PS_VALUE/PS_POSITION/PS_CASH values (0,1,2) had the wrong semantics.
Code wins (feedback_trust_code_not_docs): ps[0]=position, ps[1]=cash,
ps[2]=portfolio_value. All 148 raw ps[digit] accesses in
experience_kernels.cu and trade_stats_kernel.cu migrated. In-comment
range references (e.g. "ps[30..37]") left as documentation.
trade_stats_kernel.cu: migrated base+14 offset to PS_KELLY_WIN_COUNT.
docs/dqn-named-dims.md: PS_* table corrected to match actual code layout.
No behavioural change; pure refactor.
Plan 1 Task 4A. Spec §3 Invariant 8.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>