Generic ferroptosis-defense-factor abundance/activity switch motif

The minimal, reusable motif for set-point control of a ferroptosis-defense factor: a defense node - a suppressor whose activity is part_of negative regulation of ferroptosis (GO:0110076) - is held between two opposed arms. A destabilizer arm lowers the suppressor's abundance or activity (it directly negatively regulates the defense node and is itself part_of positive regulation of ferroptosis, GO:0160020), and a stabilizer arm preserves or restores it (it directly positively regulates the defense node and is part_of negative regulation of ferroptosis). The net ferroptosis set-point is the balance of the two arms acting on the shared defense node. Unlike molecular-function-tiered motifs (e.g. the MAPK relay, where every realization shares the MAP3K/MAP2K/MAPK function terms), the tiers of THIS motif are unified by causal role and topology, NOT by a shared molecular function. Two curated GO-CAM realizations make this explicit with completely different machinery: SLC7A11 is destabilized by a CRL3 ubiquitin ligase (CUL3-KCTD10-RBX1) and rescued by a deubiquitinase (USP18); GPX4 is destabilized by chaperone-mediated autophagy (HSPA8-LAMP2) and stabilized by EGLN3/PHD3 prolyl hydroxylation. Concrete realizations therefore embed this motif through `conforms_to` with status WITH_DEVIATIONS - matching the destabilizer/stabilizer topology while substituting instance-specific tier functions - rather than the EXACT status used by shared-function cascades.

Reusable conformance target. A node declares `conforms_to: [{template: ferroptosis_defense_factor_switch, status: WITH_DEVIATIONS, deviations: [...]}]` when an opposed destabilizer/stabilizer pair sets the abundance or activity of a ferroptosis-defense factor. The WITH_DEVIATIONS status is expected, not exceptional: the motif deliberately does not fix the tier molecular functions (a CRL ligase, a CMA adaptor, a DUB, or a dioxygenase may fill an arm), so realizations match the topology and list their instance-specific tier functions as deviations.