c_RS

The SI Bridge Closure module fixes the unique calibration from RS-native units to SI. In the native gauge the framework predicts the dimensionless triple $c=1$, $\hbar=\varphi^{-5}$, $G=\varphi^5/\pi$, together with the recognition/Planck identity $G\cdot\pi\cdot\hbar=\lambda_{\mathrm{rec}}^2\cdot c^3$ at $\lambda_{\mathrm{rec}}=\ell_0=1$.

Three positive conversion factors $a_T$ (sec/tick), $a_L$ (m/voxel), $a_M$ (kg/coherence-mass) match those native predictions to the SI values of $c$, $\hbar$, and $G$. The $c$-constraint is $c_{\mathrm{SI}}=c_{\mathrm{RS}}\cdot a_L/a_T$. Setting the native speed to 1 is the pure gauge choice that one tick advances one voxel.

Sibling constants in the same module fix $\hbar_{\mathrm{RS}}=1/\varphi^5$ and $G_{\mathrm{RS}}=\varphi^5/\pi$. Homonyms named $c_{\mathrm{RS}}$ elsewhere (baryon washout prefactor, black-hole leading-log coefficient) are unrelated quantities.

Definitional assignment only: the real constant is set equal to $1$. No lemmas, tactics, or algebraic reduction. The body is the literal numeral that encodes the native gauge $\ell_0/\tau_0=1$.

This constant is the $c$ leg of the native triple that the SI bridge closes against. With $\hbar_{\mathrm{RS}}$ and $G_{\mathrm{RS}}$ it feeds the three matching constraints whose unique solution is $a_T^2=\pi\cdot\hbar_{\mathrm{SI}}\cdot G_{\mathrm{SI}}/c_{\mathrm{SI}}^5$, i.e. $\tau_0=\sqrt{\pi},\tau_{\mathrm{Planck}}$.

Downstream, the same symbol is reused heavily in cosmology (eta-B prefactor bounds and positivity) and gravity (propagation speed, black-hole entropy ledgers), so the native $c=1$ choice propagates into those calibrations. In the forcing chain it sits with the RS-native unit conventions $c=1$, $\hbar=\varphi^{-5}$, $G=\varphi^5/\pi$ from the primer. The module status is structural closure (zero sorry): the conversion map is unique once the dimensional anchor is supplied; this definition is the $c$ anchor of that map.