07 — UI Handoff After Graph Commit

The UI consumes one view: v_registries_pivot_node_contract

No other source, no recomputation. The hierarchy is now live in the same view, so the old /knowledge/registries column→layer drill philosophy is preserved with backend data.

Fields the UI reads (verbatim)

field	use
node_code, label	node identity + display
parent_code, is_root, has_children, child_pivot_codes[], child_layer_kind	tree structure (data-driven)
count_value, count_status (pivot_backed/PIVOT_MISSING)	the number + whether it exists
final_substrate_ref	L3/L4 terminus (source table) for leaves; NULL for parents
detail_route, drilldown_query_ref	navigation
orphan_count, phantom_count, unmanaged_count (NULL=missing), drift_status	OS-Agency safety columns
pin_state (PIN_REGISTRY_MISSING), warning_flags (jsonb)	badges

Live layer examples for the UI

• Layer 1 row set: PIV-019 birth_registry 1,131,998 · PIV-007 DOT 309 · PIV-207 approvals 211 · PIV-001 catalog 169 · PIV-009 collections 168 · PIV-016 species 42 · PIV-015 triggers 107 · PIV-005 workflow-steps 70 … (24 roots).
• A DOT row in L1 / its drill: PIV-007 (309, has_children=true) → child PIV-104 (DOT theo Nhóm).
• Layer 2 group/category list: PIV-104 → pivot=8, (null)=4, Vòng đời thực thể=2, Giám sát hệ thống=2 (⚠ published-only; banner that Σ16 ≠ 309). PIV-101 → 6 composition drills (PIV-201..206).
• Layer 3 substrate example: PIV-015 → final_substrate_ref='trigger_registry'; PIV-019 → birth_registry.

What the UI must NOT compute

• count — read count_value only.
• layer depth / hierarchy — read parent_code / has_children / child_pivot_codes only (no hardcoded depth, no naming-convention inference).
• child existence — read has_children.
• group dimension — read child_layer_kind.
• orphan / phantom / drift / unmanaged — read the dedicated columns; render PIVOT_MISSING / NULL as honest "not yet defined", never as 0.

Mandatory honesty banners

• A PIVOT_MISSING badge + next_action=propose_pivot wherever count_status=PIVOT_MISSING.
• Never render unmanaged_count=NULL as 0; render as "not yet ratified".
• Surface the PIV-104 published-only drill gap (Σ16 vs 309) rather than hiding it.

Route behavior

• /knowledge/registries-pivot → renders the node contract tree (now hierarchical).
• Future parity/redirect with /knowledge/registries → the old column/layer philosophy maps 1:1 onto L1 roots → L2 children → L3 substrate. No reinterpretation of layer philosophy is needed by the UI.

Conclusion

UI can proceed directly from the backend contract. The graph commit required zero view or UI change — the same view simply now reports has_children/child_pivot_codes for the 6 parents.