PAPER_1161: Factorial Barrier Closure: 26! = (1)_{26} from 26-fold Radial Derivative (G8 Closure)

We close gap **G8** of the Lagrangian re-derivation outline by identifying the $26!$ factorial barrier in the $G$ closure (PAPER_593) as the **Pochhammer rising factorial $(1)_{26}$** arising from the 26-fold iterated radial derivative of the Newtonian Green's function $1/r$ at the bosonic critical dimension $D_{\rm crit} = 26$. The identification is **already explicit in the codebase** ([QCalcGeom.cpp L450](QCalcGeom.cpp#L450), [L458](QCalcGeom.cpp#L458)) but was not previously catalogued as the structural origin of the $26!$ appearing in $G_{\rm UQFF}$. The square $(26!)^2$ in the $G$ closure denominator is the natural consequence of varying a 26th-order multipole coupling on **both** sides of the Einstein-like field equation: kinetic term and source term each contribute one factor. ---
