nx_tropism.nx

nx_tropism.nx -- location-policy resolver. Biological analogue: tropism is a directional growth response to a stimulus gradient (phototropism toward light, geotropism toward gravity, chemotropism toward nutrient). Nishi tropism resolves a homeostasis migration signal into a concrete destination by consulting the cell's declared preference list against current conditions. Same .nx pathway runs local/NAS/peer/cloud transparently per [[feedback-pathway-tropism-block-composition-location-agnostic]]. The structural EXCEED-axis vs K8s scheduler / Nomad / Argo: those resolve placement at submission time and re-schedule on failure; nx_tropism resolves PER MIGRATION SIGNAL, mid-pathway, with cell memory intact via the existing nx_chromatin replication. Composes: nx_homeostasis -- supplies the migration signal nx_attention_class -- foreground prefers LOCAL_*; idle accepts CLOUD nx_budget -- destination must have headroom for the cell nx_pathway -- pathway declares per-cell tropism preference V1 ships a sealed enum of 10 location targets + a resolver that picks based on signal + attention class. Cost / bandwidth / latency estimation per peer is queued (requires peer-mesh discovery layer). Gap list (V1 honest perf verdict): - no actual peer discovery (returns symbolic target, not address) - no cost estimation (CHEAPEST returns same as LOCAL_DISK) - no FOLLOW_INPUT/FOLLOW_DEST cross-cell resolution (returns LOCAL_CPU placeholder) - no failed-migration retry policy (caller's responsibility) genealogy_id: nishi_cardinal_2026-05-17_pathway_tropism + biology_directional_growth lineage_id: substrate_tropism_v1 nx_safety_envelope: intended_use: "Resolve homeostasis migration signal into a concrete location target per cell preference" sil_target: SIL1 evidence: [enum_sealed, deterministic_resolution,