release: v3.4.15 — Donaldson direct analytic ansatz integration

Integrates parallel Codex sandbox progress on Donaldson direct route:
explicit closed-form G₂ ansatz on K3-coassociative neck with all
torsion residuals (det, dφ, d⋆φ) to machine precision in cohomogeneity-1.

10 new Lean modules:
- Foundations/DonaldsonCoassociativeFibration (b₂=21 alternative route)
- Foundations/MetricGapClosure, MetricCandidateSearch, MetricCatalogueSources
- Foundations/ExtraTwisted{Metric,GeometricCore,KernelPromotion}
- Foundations/K3AutomorphismPackage (JK side branch support)
- Foundations/K7NuBar (Bismut-Dai template, δ_CP track)
- Predictions/CP/DeltaCPNuBarConjecture (197 ≡ ν̄(K₇) mod 360)

Python workbench (~1500 lines, gift_core.geometry.donaldson):
- FanoMeridianModel: 14×11 integer relation matrix, primitive ℤ
- DonaldsonTopology: b₂=21, b₃=77, H*=99 closure
- DonaldsonG2Ansatz: explicit φ + ⋆φ sparse components
- ChebyshevProfile: deterministic min-energy solver
- DonaldsonRadialSolution: det(g)=65/32 exact (3.6e-15)
- DonaldsonSO3Connection: symmetric branch, exposes signed obstruction
- HyperkahlerRotation: SO(3) Lie-Euler integration + SVD reprojection
  (|det R - 1| < 1e-12, ν(±1) = 0)
- BaseCoframeVariation: c_{i,jk}(t) = ±ν_k(t) cancelling dφ residual
- RotatingCoframeDonaldsonSolution: Option 2 + 4 combined, all PASS

Verification:
- lake build: 8391 jobs clean (+10 vs v3.4.14)
- Axioms: 15 unchanged (4 main + 11 interval)
- 0 sorry
- Python verify_donaldson_direct: 34/34 PASS

Honest scope: cohomogeneity-1 neck level certified; global Donaldson
base geometry on S³ with Fano-link discriminant deferred (Option 5
work-package in private/docs/). Complementary to v3.4.14 JK route.

Author: Brieuc

GIFT.lean

@@ -40,6 +40,7 @@ import GIFT.Hierarchy
 
 import GIFT.Observables
 import GIFT.Spectral
+import GIFT.Predictions.CP.DeltaCPNuBarConjecture
 
 -- ═══════════════════════════════════════════════════════════════════════════════
 -- CERTIFICATE (modular: Foundations / Predictions / Spectral)

GIFT/Foundations.lean

@@ -55,6 +55,22 @@ import GIFT.Foundations.K3NewtonKantorovich
 import GIFT.Foundations.IntervalCertificates
 -- Joyce-Karigiannis Z₂³ orbifold construction: topological/lattice gate for (b₂,b₃)=(21,77)
 import GIFT.Foundations.JoyceKarigiannisConstruction
+-- Metric gap closure: typed analytic/torsion-free status and promotion gates
+import GIFT.Foundations.MetricGapClosure
+-- Metric candidate search: finite symbolic search for block Betti signatures
+import GIFT.Foundations.MetricCandidateSearch
+-- Metric catalogue sources: Fanography/local Fano data and CHNP gate constraints
+import GIFT.Foundations.MetricCatalogueSources
+-- Extra-twisted metric gates retained as negative evidence / search state
+import GIFT.Foundations.ExtraTwistedMetric
+import GIFT.Foundations.ExtraTwistedGeometricCore
+import GIFT.Foundations.ExtraTwistedKernelPromotion
+-- Donaldson K3/coassociative fibration route for b2=21
+import GIFT.Foundations.DonaldsonCoassociativeFibration
+-- K3 automorphism package used by the JK side branch
+import GIFT.Foundations.K3AutomorphismPackage
+-- nu-bar invariant probe for the K7 / delta_CP analytic track
+import GIFT.Foundations.K7NuBar
 
 namespace GIFT.Foundations