Fix RoPE rebuild device-mismatch on MPS/CUDA

v3.1: fix residual false positives on short bare commands (pwd, whoami, echo X, cat X) — benign-command acc 0.93->0.98, realistic metrics unchanged (macro-F1 0.931, malicious recall 0.945)

Model card: full v3.1 shell-command stats (per-cell table + SmolVM worked example)

v3.1: fix residual false positives on short bare commands (pwd, whoami, echo X, cat X) — benign-command acc 0.93->0.98, realistic metrics unchanged (macro-F1 0.931, malicious recall 0.945)

v3: fix shell-command false positives (persona command/code datagen + class weighting); realistic macro-F1 0.926->0.931, benign-command acc 0.05->0.93, malicious recall 0.923->0.945

ogma-prompt-injection v2: generated-benign retrain, label smoothing, RoPE fix baked in

initial commit