System first.
Center later.

RadialSystemSeed {
  radialSystemSchemaRef,
  hubAttachmentRef: null,
  radiusBandAttachmentRef: null,
  sectorAttachmentRef: null,
  scoringAttachmentRef: null,
  metricResultRefs: [],
  status,
  mutationAllowed: false
}

Downstream modules attach new records. They do not rewrite 23.00 root identity.

Tests cover eligibility conflict preservation, bounded explicit subject selection, exact 2D frame/position lineage, explicit radial membership, missing/duplicate/foreign binding semantics, immutable seed, zero metrics and strict 23.01–23.04 / Topic21–22 ownership firewalls.

{
  "module": "Compo 23.00",
  "name": "radial_system_schema",
  "version": "1.0-canonical",
  "canonical_main_title": "Radial system schema",
  "topic": "23_РАДИАЛЬНЫЙ_БАЛАНС_И_ЦЕНТРАЛЬНЫЕ_СИСТЕМЫ",
  "scope": "EXPLICIT_RADIAL_SYSTEM_SUBJECTS_OWNER_QUALIFIED_2D_POSITION_BINDINGS_MEMBERSHIP_INTENTS_ROOT_SCHEMA_AND_IMMUTABLE_SEED_ONLY_WITHOUT_HUB_DETECTION_POLAR_COORDINATES_RADIUS_BANDS_OR_SECTOR_SCORING",
  "main_topic_contract": {
    "topic_title": "Радиальный баланс и центральные системы",
    "topic_goal": "Формализует радиальные композиции: hub, rings, radius bands, angular sectors и распределение элементов вокруг центра.",
    "expected_output": "RadialGroupDescriptor, hub, rings, sectors",
    "planned_files": [
      "23.00 Radial system schema",
      "23.01 Hub/center detection",
      "23.02 Radius bands and orbital groups",
      "23.03 Angular spacing / sector occupancy",
      "23.04 Scoring, generator and tests"
    ]
  },
  "ownership": {
    "owner": "Compo23.00",
    "owns": [
      "RadialSubjectEligibilityEvidence",
      "RadialSubjectEligibilityResolution",
      "RadialSubject",
      "RadialSubjectSetPolicy",
      "RadialSubjectSet",
      "RadialCoordinateFrameBinding",
      "RadialPositionBinding",
      "RadialMembershipIntent",
      "RadialSystemPolicy",
      "RadialSystemSchema",
      "RadialSystemSeed root identity",
      "explicit subject-to-system membership lineage",
      "identity/status/provenance rules for Topic23 root schema",
      "non-mutating correction request for eligibility/frame/position/membership/schema errors"
    ],
    "does_not_own": [
      "raw geometry or point measurement — upstream geometry owners",
      "hub/center detection or hub descriptor — Compo23.01",
      "polar radius/angle derivation — Compo23.02/23.03",
      "radius bands, rings and orbital groups — Compo23.02",
      "angular spacing and sector occupancy — Compo23.03",
      "approximation/scoring/generator/MetricResult — Compo23.04",
      "symmetric balance / mirror correspondence — Topic21",
      "asymmetric centroid/moments/counterweights — Topic22",
      "dominance / hierarchy / beautyScore / final-layout ranking",
      "foreign geometry/style/semantic mutation"
    ]
  },
  "consumes": [
    "explicit foreign object/element identities",
    "explicit radial-system subject eligibility evidence",
    "explicit owner-qualified 2D coordinate-frame binding",
    "explicit owner-qualified subject position refs in that frame",
    "explicit radial membership intents",
    "optional source/provenance metadata"
  ],
  "provides": [
    "RadialSubjectSet",
    "RadialCoordinateFrameBinding",
    "RadialPositionBinding[]",
    "RadialMembershipIntent[]",
    "RadialSystemSchema",
    "RadialSystemSeed"
  ],
  "owns_metrics": [],
  "independent_numeric_votes": 0,
  "status_semantics": {
    "OK": "valid explicit schema lineage",
    "N_A": "missing/conflicting/not-applicable evidence; never numeric zero",
    "INVALID": "malformed or impossible record; never numeric zero"
  },
  "policy": {
    "selectionMode": "EXPLICIT_SUBJECTS_ONLY",
    "membershipMode": "EXPLICIT_INTENTS_ONLY",
    "maxSubjects": [
      1,
      4096
    ],
    "maxMembershipIntents": [
      1,
      4096
    ],
    "overflow": "N_A_WITHOUT_TRUNCATION",
    "autoHubDetection": false,
    "autoRingDiscovery": false,
    "autoSectorDiscovery": false,
    "autoScoring": false
  },
  "root_seed_contract": {
    "radialSystemSchemaRef": "exact",
    "hubAttachmentRef": null,
    "radiusBandAttachmentRef": null,
    "sectorAttachmentRef": null,
    "scoringAttachmentRef": null,
    "metricResultRefs": [],
    "mutationAllowed": false
  },
  "firewalls": [
    "radial membership != geometric ring membership",
    "radial membership != semantic importance",
    "coordinate-frame origin != hub",
    "position binding != polar radius/angle",
    "subject near frame center != hub",
    "equal radius is not inferred in 23.00",
    "angular sector is not inferred in 23.00",
    "radial system != symmetric balance",
    "radial system != asymmetric balance",
    "N_A != 0",
    "INVALID != 0",
    "descriptor != score",
    "local != global",
    "geometry != interpretation"
  ],
  "hooks": {
    "IDEAS_REFS[]": [
      "radial-layout synthesis",
      "nested radial systems",
      "hub ambiguity studies",
      "ring perception",
      "angular rhythm",
      "intentional asymmetry around hubs",
      "multi-center composition"
    ],
    "DATA_CAPTURE[]": [
      "eligibility",
      "frame lineage",
      "position-binding lineage",
      "membership intents",
      "root-schema identity"
    ],
    "DEFERRED_SEMANTIC_INPUTS[]": [
      "hub evidence",
      "ring tolerance",
      "sector tolerance",
      "style intent",
      "target fit"
    ],
    "HUMAN_FEEDBACK_HOOKS[]": [
      "subject inclusion correction",
      "frame correction",
      "position binding correction",
      "membership correction"
    ],
    "CONFLICT_PRIORITY_ASSUMPTIONS[]": [
      "confidence does not choose winners",
      "frame origin has no hub priority",
      "membership order has no radial priority"
    ],
    "LAB_HOOKS[]": [
      "perceived center vs geometric center",
      "ring grouping thresholds",
      "sector occupancy perception"
    ]
  },
  "topic23ProgressAfterThisModule": "1/5 local",
  "next_module": "Compo 23.01 — Hub/center detection",
  "hard_stop": "No 23.01–23.04 implementation in this file"
}