_apply_action_plan: constrain the target KPIDefinition lookup to sug.entity_id so a
suggestion whose target_id/suggestion_data.kpi_id points at a foreign-entity KPI now
returns 404 instead of creating an ActionPlan row with a cross-entity kpi_id.
preview_suggestion: same constraint; a foreign-entity KPI now degrades to the existing
placeholder (KPI#<id>, current_target=None) instead of echoing the foreign KPI name and
current_target. Degradation (not 404) keeps the read-side preview usable when the stored
kpi_id is inconsistent.
Regression: backend/tests/test_ai_suggestion_kpi_attribution_residual_20260918.py
(RED 2 failed before, GREEN 5 passed after; full suite 1228+2F -> 1230 passed / 1 xfailed).
Hermes CI Fix
557771a803