dismiss_suggestion: add get_entity_id dependency and filter AISuggestion.entity_id (cross-entity dismiss returned 200 and mutated the foreign row).
_apply_kpi_target/_apply_budget_adjust: constrain target KPIDefinition lookup to sug.entity_id so suggestion_data pointing at a foreign KPI yields 404 instead of rewriting it.
Regression: backend/tests/test_dismiss_suggestion_entity_scope_20260918.py (RED 3 failed before, GREEN 5 passed after; full suite 1220 -> 1225 passed, 1 xfailed).
Hermes CI Fix
9cb960da25