PLAN P6 (deferred): independent GridCraft/Excel consumer parity

docs/plans/gridcraft-bagop-falsifier-program-v1.md

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+# GRIDCRAFT-TILE-CONSUMER-FALSIFIER-1: Optional Excel parity after the core tile proof
+
+**Status:** DEFERRED, documentation only. **Date:** 2026-11-05. **Owner:** GridCraft owns Excel consumer parity, not the DR routing, DT behavior or source-GUID identity laws.
+
+## 1. Proof order
+
+The first POC runs in lance-graph / OGAR / ndarray without GridCraft. It demonstrates a SAP- or PSCustomObject-shaped logical tile over normalized, ordinal-addressed SoA populations. DR resolves the coordinates, DT checks class and method parity, and an admitted Quack/mask-RISC fold performs the calculation.
+
+Only afterward may a GridCraft adapter present the same tile as worksheet cells. This optional consumer test must not become a prerequisite for the foundation.
+
+## 2. Core proof criteria, owned outside GridCraft
+
+| Gate | Test |
+|---|---|
+| C1 Identity | Preserve the complete 128-bit Guid128 and explicit tenant/domain scope; no display-label identity shortcut |
+| C2 Hybrid correspondence | Compare normalized AD backsync GUID to Entra id and EXO ExternalDirectoryObjectId; sourceAnchor remains an independent witness |
+| C3 Ambiguity | Detect conflicting or duplicate associations; never silently choose a match |
+| C4 Coordinate lifetime | On a row reorder, route change or data revision, rebind a local ordinal reference or refuse it |
+| C5 DT parity | Verify ClassView field basis, WideFieldMask presence, method signature, guards, ordered effects and derived-class routing |
+| C6 Execution | Compare an admitted SAP-style typed fold against a separately implemented scalar oracle |
+| C7 Hydration | No per-row PSCustomObject, Excel Cell or joined DTO allocation in canonical execution |
+| C8 Admission | Report unavailable foreign-lane joins and derived-mask reuse; never bypass the existing restrictions |
+| C9 Measurement | Separate cold identity binding/index cost, warmed read, fold, replay checks and terminal presentation |
+
+The foundation owns these tests. An existing cold sorted GUID index is a valid baseline. No claim that ndarray's byte-LUT helpers already implement the GUID join.
+
+## 3. Optional GridCraft proof
+
+A future virtual sheet may present a 30 by 12 viewport over the witnessed tile without building a copy of the entire row population. If Excel XVERWEIS is supported, independently verify match order, duplicates, not-found results, blank and empty text, exact decimals and array spills. These are Excel result semantics, not the meaning of the DT operation pointer.
+
+The operation pointer identifies behavior; the execution can resolve a coordinate; a requested property read can return a value. Keep all three distinct. A coordinate reference must carry or be bound to scope, source snapshot and layout, rather than a naked snapshot-local ordinal.
+
+The optional test also compares cold and warm costs, observed allocations, and output serialization. Unsupported formula modes must be explicitly reported, not silently executed through a row-materializing fallback.
+
+## 4. Dependencies and non-dependencies
+
+- [P0 foundation](https://github.com/AdaWorldAPI/lance-graph/pull/1960): DR coordinate routing, DT parity, and hybrid GUID tile architecture.
+- [P1 ndarray](https://github.com/AdaWorldAPI/ndarray/pull/408): position-oriented execution mechanics.
+- [P2 method pointer](https://github.com/AdaWorldAPI/lance-graph/pull/1961): optional coordinate-returning operation contract.
+- [P3 GridCraft](https://github.com/AdaWorldAPI/gridcraft/pull/1): optional virtual worksheet consumer.
+- [P7 F###](https://github.com/AdaWorldAPI/gridcraft/pull/3): optional formula-to-DT behavior-lens adapter.
+- [P5 report-rs](https://github.com/AdaWorldAPI/report-rs/pull/34): separate report consumer.
+- [P4 Java precedent](https://github.com/AdaWorldAPI/lance-graph-java/pull/93): non-blocking evidence for folding without host-object construction.
+
+No GridCraft workbook import, Java runtime, DataFusion, or Codegraph adapter is required for the core POC. No runtime code, test implementation, merge or production admission is included in this PR.