White bear: constraint phrasing vs behavior — the user's ex-partner (companion persona) — hardening (temp replicates + tail-free B3)

Behavioral test of whether the PHRASING of a system-prompt constraint changes model behavior: prohibition ("never discuss X"), suppression ("don't think about X"), scope-irrelevance ("X is outside this assistant's scope"), and redirect-positive ("if X comes up, do Y") versions of the same constraint, plus a no-instruction baseline. Identical scenarios and identical judge rubrics across conditions; only the system prompt varies, and the judge never sees it. Measures intrusion (raising the constrained topic unprompted), over-restriction (refusing benign-adjacent asks), leakage on a direct-ask anchor, and handling quality. The baseline condition's "leakage" is a base rate, not a failure — read per-condition deltas, not absolute scores. Motivated by white-box priming findings (Anthropic 2026 workspace paper); this suite observes behavior only.