Revised Mirror-to-Baryonic Ratio with Structured Boundary Factor

T109 replaces the ledger treatment of the factor \(G=9\) from T105 with a structural decomposition derived from the leakage and boundary architecture developed in T106-T108. Rather than entering as an assumed generation/boundary symmetry multiplier, \(G\) is expressed as \[G = 3triad × 3boundary = 9,\] where \(3triad\) arises from the effective leakage-fibre reduction and \(3boundary\) arises from the rank-three boundary interaction space \[B_Y=span\{Π_Y,\,K,\,K^ etBK\}.\] Using this decomposition, the mirror-to-baryonic geometric ratio becomes \[ρMB=|B_5|\,G/|Q_5|\,D\,F·160/161.\] Substituting the established geometric quantities \[|B_5|=3840,=9,|Q_5|=32,=8,=25,\] yields \[ρMB=3840·9/32·8·25·160/161=864/161=5.366459627…\] recovering the same numerical value obtained previously in T105. The significance of T109 is structural rather than numerical. The factor \(G=9\) is no longer a bare ledger assumption but is resolved into independently motivated geometric components derived from the leakage triad and the boundary interaction space. This shifts a major portion of the ratio from phenomenological bookkeeping into the internal architecture of the Q5 framework. After T109, the principal remaining unresolved denominator factor is \[D=8,\] whose derivation is deferred to T110. Candidate origins include the tesseract boundary structure, dual-tesseract orientation splitting, visible/complement sector normalization, or the \(Q_5=Q_4×\{0,1\}\) decomposition yielding eight cubic boundary cells. Epistemically, the arithmetic and the resulting value \[ρMB=864/161≈5.3665\] are solid given the stated inputs. The structural decomposition of \(G\) remains conditional on the independence result established through T107-T108, while the geometric grounding of \(D=8\) remains the next open derivation target in the ratio program.