The gauge-hierarchy problem — the fourteen-order-of-magnitude chasm between the Planck and electroweak scales — and the cosmological-constant problem collectively constitute the deepest structural wounds in the standard model of gravitation. Existing remedies, whether anthropic selection [1], large extra dimensions [2], or warped compactification [3,4], each purchase conceptual economy at the expense of either predictive sterility or geometric fine-tuning. This framework develops upon effective-field that welds three architecturally cohesive structures: an F(R) = R + αR2/M∗2 − 2Λ5 bulk action in five dimensions, a circular Kaluza–Klein (KK) compactification whose radius RKK is fixed by a light stabilised radion of mass mφ ∼ H0, and the Hartle–Hawking no-boundary wave functional as the cosmological boundary condition. Within this architecture the KK tower generates an analytically controlled repulsive correction to the Newtonian potential above a comoving threshold λ ∼ c/H0 ≈ 1 Gpc, the effective cosmological constant receives a geometrically negative KK contribution that partially cancels the vacuum energy without anthropic invocation, and the scale-dependent effective Newton constant Geff(k, a) offers a possible resolution the σ8 tension — predicting σ8 = 0.769 against the lensing-derived 0.766 ± 0.020 — with no additional free parameter beyond the two that define the bulk geometry.