A new research contract (alongside U_wall, G_metric and CONTRACT.F.01), typed as a numbered chain of work packages with pre-registered kill tests — not a claim. Hypothesis (as corrected by WP1): the seam is the glue-equivariant ℤ₄-orbifold sector of the celestial chiral algebra on the A₃ ALE space ℂ²/ℤ₄; the μ₄ clock is the Kähler U(2) phase diag(i,1) whose square is the deck group (spin bridge ℤ₈, 8 = 2|μ₄| — the c₃ = 1/(8π) winding integer); the twistorial bulk is the SELF-DUAL sector of TFPT gravity only. The spin bridge is no longer a bookkeeping convention: the NS deck implementation is forced to order 4 (U² = (−1)^F exactly, nonsplit ℤ₄; v506), and the nonsplit class is arrangement-sensitive — the edge (silver) arrangement splits (U² = +1, zero roots), so the seam fermions MEASURE the v506 alignment bit as a Fidkowski–Kitaev-type extension class (v507, SEAM.BIT.ORIGIN.01). WP1 is executed and verified (v492, sympy exact, verdict B): the E₈ μ₄-glue grading (v128) is INNER — h = (2,2,2,2,2;0⁴) reads the glue class mod 4 on all 240 roots, so the glue is a flat ℤ₄ monodromy in the Kronheimer–Nakajima sense, with the A₃-side detector reading the same diagonal (1,1) glue of ℤ₄×ℤ₄ (v92/v125); ℂ²/ℤ₄ is verified as the A₃ singularity XY = Z⁴; the glue-equivariant SDYM(E₈) sector closes with graded dimensions 60(d+1)/64(d+1) — possible only because dim g_j = (60,64,60,64) — zero modes = the carrier D₅⊕A₃+Cartan = 60, density 1/4 = 1/|ℤ₄|; the four glue-sector characters sum exactly to the (E₈)₁ character 1+248q+4124q²+34752q³ (v377), with sector weights = the v92/v125 discriminant form (5x²+3y²)/8 and integer glue-diagonal h = (0,1,1,1) (= locality of the (E₈)₁ extension). The critical correction (why verdict B): the A₃ deck acts on the celestial sphere as z → −z (order 2, the sheet flip), NOT as the order-4 clock z → iz; the clock is the U(2) phase diag(i,1) (normalising the deck, det = i rotating the holomorphic symplectic form by the μ₄ generator), with the exact spin bridge (spin clock)² = deck. Clock-invariance selects the 1-parameter A₃ deformation XY = Z⁴ + a₀ whose four branch points are one μ₄ orbit with cross-ratio 2 (the v168/v214 pillowcase marks). Negative controls kill the false spatial action diag(i,i) three ways and the false glue (3112/6720 additivity violations); rigidity = Aut(ℤ₄). Typing/non-circularity: the continuum existence of the (E₈)₁ net on the seam — the SEAM.EQUIV.01 target — is NOT an admissible input. WP2 is now also executed and verified (v493, sympy exact, 47 checks, verdict B): the clock-invariant deformation XY = Z⁴ + a₀ is selected SHARPLY (P(iZ) = P(Z) forces a₃ = a₂ = a₁ = 0, two-sided), is smooth iff a₀ ≠ 0 (disc = 256a₀³), and its binary-quartic invariants are I = 12a₀, J = 0 identically — so j = 1728 and the τ = i pillowcase shape (v168/v214) is FROZEN for every a₀: a₀ is a pure seam SCALE, no shape modulus survives clock-invariance (negative controls: a₁Z gives j = 0, an a₂-instance gives j = 1556068/81 — the test has teeth). The three resolution spheres carry exactly the three nontrivial μ₄ characters {i,−1,−i} under the clock, which acts on H₂ as a Coxeter element of W(A₃) (char x³+x²+x+1, h(A₃) = 4 = |μ₄| = N_fam+1), fixes no cycle, and IS the Picard–Lefschetz monodromy of the family; the surviving direction is the weight-1 χ₁-Fourier diagonal (1,i,i²), all three sphere volumes in lockstep (√2·t). The Bittleston–Homans–Sharma deformed-algebra pattern transfers ℤ₂ → ℤ₄: the fibre bracket −4·Nambu(XY−Z⁴−a₀), anchored at the a₀ = 0 orbifold, closes with corrections exactly linear in a₀ at the ℤ₄ wrap, conserving the μ₄ grade (no sector leak — the WP1 equivariant sector deforms consistently), with a₀ in BHS's weight-0 c² slot; verdict B via three named identifications (−4·Nambu as THE k = 4 CCA bracket; period = root difference; seam-scale reading via clock² = deck). The v216 residual is typed, not moved: given the order-4 clock the square is automatic — a relocation of the same order-4 carrier input, not a new derivation. WP3 is executed and verified (v495, exact Fraction/sympy, 25 checks, verdict B): the Okubo coefficient 5/(2(dim g+2)) is DERIVED as a polynomial identity for all 8 algebras on Costello's list (sl₄ negative control: 5/32 vs 3/32), the closed form λ̃² = 10h∨²/(dim+2) = h∨+6 holds across the Deligne series, and for E₈ the Green–Schwarz coefficient is exactly λ̃ = 6 (unit-trace) resp. λ_fund = 1/10 (adjoint-trace), so (κ/c₃)² = 12 = |μ₄|·N_fam resp. 1/300 — exact anchor rationals, with κ/c₃ itself irrational (2√3; a byproduct: the printed λ²(so₈) = 3/2 in Costello's appendix A is a factor-2 slip, the exact value is 3). The look-elsewhere caveat is part of the result: the same squared-rational alignment holds for ALL eight algebras (8/8 — zero selective power), λ̃-integrality passes 2/8 (shared with sl₃), and the only E₈-selective single test is g_car = 5 | h∨ (1/8); the isolating conjunction is post hoc. Alignment survives; selectivity does not — the c₃-connection is convention-level compatibility plus genuine λ-arithmetic, NOT E₈-selective evidence, and never a derivation of c₃. WP4 is executed and verified too (v496, exact integer/Fraction/sympy, 25 checks, verdict B(ii)): the (E₈)₁ character E₄/η⁸ = (1, 248, 4124, 34752, 213126, …) is NOT a conformal block of the celestial E₈[ℂ²] S-algebra in its own jet grading — the obstruction is localised three ways: (a) the CP grading gives spin 1 − d/2 unbounded below and 248 is never a jet-tower dimension (d ≤ 100); (b) the cumulative generator count is quadratic (31s²+92s+60, 31 = k+h∨), so the jet Fock grows as n^(2/3) against the character's n^(1/2) (f_n/χ_n strictly increasing, n = 1..12); (c) the level-2 null ideal of (E₈)₁ deletes exactly 27000 = 30³ = h∨³ out of Sym²(248) = 1+3875+27000 (the character keeps 4124 = 1+248+3875) — with no jet analogue. But the boundary/period reading holds exactly at the current stratum: the zero-mode slice is the 60 vacuum-sector currents, the jet slice cycles (60,64,60,64), one full μ₄ period of loop energies sums exactly to 248, and the glue-diagonal weights (0,1,1,1) are integers — while the free loop Fock counts 897266 ≫ 248 at level 1, so the rational truncation must be imposed in a limit. That is precisely the MMST scaling-limit shape of SEAM.EQUIV.01 (v336/v449): the character is a boundary/limit SHADOW of the S-algebra, and the constructive limit question passes to WP5. Kill tests evaluated: K1 survived (WP1+WP2), K3 did not fire but is scope-demoted (the alignment format passes 8/8 — compatibility, not evidence), K4 fires only against the exact-block reading (the sector arithmetic holds exactly, so no degradation to 'E₈ admissible'). WP5 is subdivided WP5a–e, and its first milestone WP5a is executed and verified (v497, exact integer/Fraction, 34 checks): the WP4 boundary-limit shadow is made a PRECISE coefficientwise limit — the one-parameter family χ_w of graded Fock characters on the chiral jet generators (E_w = m + w·r in quarter units u = q^(1/4)) contains the chiral jet grading as its w = 2 member (generator counts 64, 120, 128, 180, 192, 240, 256, 300) and its u^n coefficient equals the quarter-moded loop Fock for ALL w ≥ n+1, strictly larger for w ≤ n (n ≤ 8, w ≤ 10) — an explicit stabilisation threshold w = n+1, not a slice; and the null ideal is DERIVED from root data, not cited: Freudenthal + Weyl + character peeling give Sym²(248) = 27000 + 3875 + 1 with residual exactly zero, 27000 = 30³ = h∨³, and the level-2 quotient 31124 − 27000 = 4124 = 1+248+3875 equals the independent μ₄ theta-split sector sum (1036, 1024, 1040, 1024) at q² — two routes, one number. Negative controls: SO(16)₁ through the same pipeline gives FOUR components (5304+1820+135+1), 5304 ≠ 14³ (h∨³ is not generic), quotient 2076 = Θ_D8/η⁸ (the recipe validated on a second algebra), and block weights (0, 1/2, 1, 1) that cannot fuse into one local character; only P = 4 = |μ₄| periodisation reproduces the 248 layer. Honest limit: the limit does NOT generate the truncation (loop Fock 897266 ≫ 248 at level 1) — WP5a fixes the ideal's size and location quantitatively and gives the celestial route the same two-step shape as MMST (limit + maximal ideal). The second WP5 milestone WP5b is executed and verified too (v498, exact integer/Fraction, 53 checks, deterministic — success on the preregistered criterion): the deleting object exists and is explicit — |s⟩ = (E^θ_{−1})²|0⟩ (weight 2θ, level 2 = 8 quarter units = q², an integer level) is constructed in a machine-built Chevalley/Frenkel–Kac basis (cocycle asymmetry on all 57600 pairs, the [e_α,e_{−α}] sign FORCED by Jacobi with SGN = −1, κ derived with κ(θ∨,θ∨) = 2), and J^a_1|s⟩ = 0 is machine-verified for ALL 248 generators with the case classification 190 (first bracket) / 57 (second) / 1 (a = F^θ via the central-term cancellation — the only case that sees the level k); plus J^a_2|s⟩ = 0, E^a_0|s⟩ = 0, exact weight and Shapovalov norm 0; the affine PBW engine is unit-tested on all 61504 basis pairs. Level dial: the F^θ_1 coefficient is 2(1−k) — 2/0/−2 at k = 0/1/2: without the central extension the deletion operator does not exist. μ₄ compatibility: glue class j(θ) = 1 (machine-built h-adapted chamber, ⟨θ,h⟩ = 5, height 29 = h∨−1), clock phase i^(2j) = −1, class(2θ) = 2 sheet-even with the deleting θ-sl₂ crossing the sheet-odd classes (1,3); 8 quarters = q² via the per-period dictionary. The module it generates is THE ideal: weight 2θ has multiplicity 1 in the level-2 Fock, and the direct g₀-orbit BFS reproduces the Freudenthal multiplicities of V(2θ) exactly through depth 4 (27000 = h∨³, quotient 4124; Weyl complete reducibility beyond depth 4 typed [C]). Negative controls separate honestly: the level-1 current state and generic level-2 states are NOT singular; at k = 2 the CUBE is (generic Kac (E^θ)^(k+1) mechanics); SO(16)₁ has the same singular vector but keeps three extra level-1 primaries (h = 1/2 breaks one-block fusion) — the singular-vector mechanism is level-1 generic, the ONE-BLOCK closure is the E₈/μ₄-specific part. Honest handover to WP5c: in the twisted quarter-slot moding two sector-C₁ modes never sum to 8 quarters (minimum 6 = q^(3/2)) — the per-period dictionary (v496), not the per-slot identification, carries |s⟩ to q²; exactly the GNS/limit-state question (kernel ⊇ ideal) that WP5c answers. WP5c is executed and verified (v500, exact integer/Fraction, 35 checks, success on the preregistered criterion): the quasi-free family ω_w exists — loop sector = the affine k = 1 vacuum n-point functions via the machine-determined compact anti-involution θ(e_α) = −e_{−α} (the unique anti-automorphism sign on all 61504 basis pairs), radial sector = oscillator pairings x^(wr) (the exact Gibbs regulator) — is positive for every finite w, and stabilises EXACTLY at the WP5a threshold (ω_w = ω_∞ mod x^(N+1) for w ≥ N+1, sharp at w = N). Its limit carries the null ideal in its GNS kernel: the complete 9361-block exact level-2 Gram has rank 4124 exactly (the preregistered target), kernel 27000 = V(2θ) weight by weight (Freudenthal cross-check on all 9361 weights), every block PSD, rank table per Weyl orbit (0,0,1,8,44), level-1 rank 248 positive definite (the current layer survives); the clock descends to GNS with level-2 rank split (1036,1024,1040,1024) = Θ_Cj/η⁸ at q² — the two-routes identity at the STATE level — and |s⟩ IS the zero vector of GNS(ω_∞), resolving the WP5b twisted-slot tension. A CCR obstruction shows NO w-uniform state can damp the radial modes (the family formulation is NECESSARY, and the family exists — KILL not triggered); controls: k = 2 keeps everything (⟨s|s⟩ = +4), k = 0 has no current layer, D₈ gives one block of four, the wrong family erases the 248 layer (710955 ≠ 248), no damping keeps 897266 ≠ 248. WP5d-α is executed and verified too (v501, Gaussian lattice machinery ED-validated to 1e-15 + exact Fractions, 39 checks): the KLM two-interval index measured entropically on the 16-layer seam carrier — the fermionic two-interval MI is extensive (μ = 1 reference; c fit 0.5000, residual → 0 with N) while the sector-summed orbifold prescription pays exactly one classical bit (the ln 2 plateau at machine precision, |Δ₂ − ln 2| = 1.1e-15 at N = 512), so [F:F_even] = 2 and μ_gauged = 4 = the v490 parity census (two independent lattice witnesses); the orbifold breaks two-interval complementarity S(E) ≠ S(E′) (the direct duality-failure witness) with the complementary-pair budget ≤ ln 4 = ln μ(SO(16)₁) as a double-limit statement; the condensation arithmetic is anchored at both measured ends — det Cartan(D₅)·det Cartan(A₃) = 16, KLM/Longo–Rehren 16/4² = 4/2² = 1, Σd² = (4,4,1), θ_v = 1 exactly at ν = 2c₋ = 16 (rivals ≠ 1) — so μ = 1 after condensation and the preregistered KILL ('μ-offset ≠ 0 after condensation') does NOT fire; controls: the ν = 1 offset is non-removable (θ_v ≠ 1 — the discriminator has teeth), the trivial phase shows nothing, the wrong sector sum loses the full ln 2. WP5d-β is executed and verified as well (v504, Gaussian lattice machinery ED-validated + exact GF2/integer algebra, 37 checks): the two remaining KLM legs of complete rationality witnessed for the same orbifold prescription — strong additivity is algebraically EXACT with the shared boundary Majorana (Even(A) ∨ Even(B) = Even(A∪B): GF2 spans full 64/64, 256/256, 512/512, 1024/1024, matrix rank 32/32; disjoint exactly HALF, index 2 — the missing sector odd⊗odd is the v501 ln 2 bit, localised at the split point; the neutral U(1) algebras do NOT generate the union even with the shared site, gaps 2/10/52 growing); the entropic touching defect is BOUNDED < ln 2 with the Ising ¼-exponent approach ((ln 2 − Δ₂) ~ N^(−p), p = 0.2444 vs 2Δ_μ = 1/4; honest note: 'defect → 0' would be FALSE at the sharp lattice split — bounded ⟺ finite index, Longo–Xu) while the preregistered U(1)/Dirac control bursts ln 2 from L = 128 and grows as (1/2)ln Var Q_A (Klich–Levitov slope 0.10134 vs 1/π² = 0.10132: infinite index — the current-net failure reproduced); the split property is witnessed at the elliptic-nome rate πK(1−x)/K(x) to 1.3–2.0% (σ₁ ~ x^0.5044, trace norm summable) with EXACT orbifold inheritance (P_A flips C → −C, σ_k identical to 8.3e-17; the even-bilinear coupling Gram is the second compound Λ²C — Longo heredity); and Pimsner–Popa E(a) − a/2 = PaP/2 holds identically (λ = 1/2 = 1/[F:F_even] with exact integer attainment: 16384 + 2048 monomial sweeps, 0 violations; λ_E4 = 1/4 = 1/μ; index consistency exp(Δ∞) = 2 = 1/λ_PP over two independent routes; U(1): λ = 1/(m+1) → 0): with v501 ALL THREE KLM ingredients of complete rationality — split, strong additivity, finite μ — are witnessed on the lattice; the continuum uplift is honestly fenced ('finite-group orbifolds of completely rational nets are completely rational' is Xu's theorem — cited, not claimed; the concrete seam quotient net and the interacting condensed (E₈)₁ net stay WP5e/Costello–Li). WP5e is now subdivided, with its α stage executed (v502, exact sympy/Fraction, 33 checks, CELEST.WP5E.ALPHA.01 — the CFT-side prefactor + level pinning): the q^(−1/3) prefactor of E₄/η⁸ IS exact μ₄ vacuum-energy bookkeeping — the clock is INNER ((h,h) = 20, (h′,h′) = 12, sum 32), so the twist on the 8 torus bosons is θ = 0⁸ in all four sectors (a SHIFT orbifold, not a rotation orbifold) and every sector carries the same −c/24 = −1/3 at c = 8; the sector weights (0,1,1,1) ARE Casimir energies (spectral flow j²(h,h)/32 mod 1, and exactly via the 16-Majorana seam carrier, R–NS shift n/16 = 5/8, 3/8, 1); and k = 1 is forced THREE independent ways (current condition h(J) = k = 1; conformal embedding 47(k−1)(k+266/47) = 0 resp. 128k(1−k) = 0; central charge 248k/(k+30) = 8 ⟺ 240(k−1) = 0 — the prefactor itself) plus the WP5b singular-vector dial (31124 − 27000 = 4124 at k = 1 only); honest sharpening: glue-h integrality h(J^j;k) = k(0,1,1,1) holds for ALL k = 1..8 and fixes nothing — the naive integrality route is retired; controls: D₈ has the SAME prefactor but h = (0,1/2,1,1), ℤ₂/μ₄ rotation twists break the common prefactor, wrong k ∈ {2,3,4} fails all five dials. The β stage is executed as well (v505, exact sympy/Fraction, 47 checks, CELEST.WP5E.BETA.01 — the equivariant anomaly ledger on twistor space): the Atiyah–Bott/Lefschetz fixed-point skeleton of the one-loop box anomaly on ℂ²/ℤ₄ is exact — denominators (2,4,2) with Dedekind sum 5/4 = (|ℤ₄|²−1)/12, equivariant characters (248,0,−8,0) by two routes, invariant average 60 = the carrier, Frobenius 61568; only the INVARIANT sector is Okubo-quadratic (36⟨x,x⟩², 36 = λ̃²_e8 — v495 re-derived), the twisted sectors carry irreducible T₅/T₃ content, and the AB-weighted sum cancels the D₅ quartic exactly while leaving the RIGID residual 32·T₃ (no admissible reweighting fixes it; the graded GS exchange is rank-obstructed in sectors 1–3); the index bridge f(m) = (1/4)Σ_j(i^(jm)−1)/det_j = ch₂(T_m) = −(C⁻¹)_mm/2 holds EXACTLY (fixed-point ledger = McKay/Kronheimer intersection ledger) with the integral glue defect −78 by both routes; the level dials say k = 1 geometrically (lattice current count 240 at k = 1 and exactly 0 at k = 2,3,4; embedding residual (0,360,814,1362); one scale ⇒ one level; integrality alone fixes nothing — honest, as on the CFT side); and an honest REFUTATION: the clock-invariant modulus a₀ ∈ O(8) fills the BSS GRAVITON slot O(2), not the axion slot O(−2) (weight mismatch 4 = |μ₄|) — 'the theory brings its own GS axion as a₀' is false; instead the three H²(ALE) classes carry exactly the three twisted-sector Coxeter characters {i,−1,−i} (bijection), and the bulk axion must come from the O(−2) tower field itself; controls: diag(i,i) breaks the ledger four ways, SO(16) glue gives defect −30 ≠ −78 with a failing bulk Okubo, k = 2 dies on the closure dial; the preregistered kill ('inflow demands a level ≠ 1') does NOT fire on the equivariant skeleton. The γ stage is executed as well (v508, exact sympy/Fraction, 27 checks, CELEST.WP5E.GAMMA.01 — the sphere-axion pairing check, an honest rigid NEGATIVE result): the W(D₅)×W(A₃)-invariant vertex space on the glue Cartan is exactly dim 2 (quadratics = span{s₅, s₃}) and dim 5 (quartics = span{P₁,P₂,P₃,T₅,T₃}) by Weyl nullspace arithmetic, and the PRODUCT THEOREM kills every exchange image in the T₃ direction (any two invariant quadratics multiply into span{P₁,P₂,P₃}, while Φ_T3(A_fix) = 32 ≠ 0); the strict two-index rule collapses the sphere couplings entirely, the twist-insertion channels E₁₃ = (16,−96,144,0,0) and E₂₂ = (16,32,16,0,0) give rank([M | A_fix]) = 3 with the annihilator certificate (Φ_T5, Φ_T3, Φ_P)(A_fix) = (0, 32, 72) (side discovery: K⁽⁰⁾ = −15·K⁽²⁾, the even-sector quadratics are parallel); naturalness dissolves (ch₂-natural and AB-weight couplings both certify (0,0) vs required (32,72) — scale-independent); SO(16) has no sphere partners AND uncancelled T₅, D₈ no T₃ structure; the slot bijection is untouched and the level-kill still does not fire. The remaining roadmap is WP5e proper alone (the GLOBAL BCOV/Kodaira–Spencer quantisation on PT/ℤ₄: the partition function E₄/η⁸ including the q^(−1/3) prefactor derived FROM THE TWISTOR SIDE — neither the v502 CFT-side dials, nor the v505 equivariant skeleton, nor the v508 exchange no-go trigger the kill branch; the exchange sub-branch is closed by v508, and the named remaining targets are the twisted BCOV contact terms (δ₁, binary test: the one-loop coefficient exactly (9,−30,−15,0,32), computed not fitted) and the full-tensor ledger (δ₂), plus ε₁ (the O(−2) bulk-axion construction) and ε₂ (CPS level-from-flux); the continuum uplift of the WP5d lattice witnesses is Xu's theorem, cited not claimed) — WP5a–WP5d (both WP5d stages) plus WP5e-α/β/γ are landed. SEAM.EQUIV.01 stays [O]; nothing here moves it. A compact twelve-step synthesis of the executed work packages — the narrative arc from the μ₄ clock to the (E₈)₁ boundary shadow — is presented as a dedicated section in Paper 3 (E₈ Audit & Bootstrap); this contract remains the full technical reference (typing fence, kill tests, work-package statements).