Validation, NCE analysis, per-replicate oracle for landmark/naive, RCT truths script, resumable experiment runner

- W0 harm validation (40 reps): CCW and sequential ITT unbiased for their truths (|z| <= 0.7)
- PVI models fitted separately inside and after the window
- experiments.yml grid (8 worlds x 3 scenarios; designs x V1-V4; NCE; RCTs); smoke run clean

Co-Authored-By: Claude Opus 5.5 <[email protected]>

simulations/config/experiments.yml

@@ -0,0 +1,12 @@
+# Experiment grids (plan sections 5.2, 7, 9). Run with simulations/run_experiment.R <grid> [--scale draft|final]
+main:
+  worlds: [W0, W1, W1_rho0, W2, W3, W4, W5, WR]
+  scenarios: ["null", harm, benefit_harm]
+  designs: [naive, landmark, ccw, seq]
+  variants: [V1_ignore, V3_random, V4_within]     # V1 also yields V2 (cluster-robust SE)
+  nce: true                                        # negative-control exposure (landmark, CCW), D32/D36
+  rct: [realistic, ideal]
+scales:
+  smoke: {n_patients: 20000, reps: 1}
+  draft: {n_patients: 50000, reps: 100}
+  final: {n_patients: 50000, reps: 500}                     # to be revisited after the draft (sample size, D25/D29)