Courier Reachability and a Fixed-Time Third Service in Autonomous Source Refresh

Completion of an apparatus's main processing block does not establish that its courier completes receiving before a prescribed service clock. We close this remaining obligation for a retained 68-coordinate autonomous source-refresh family with finite supplies installed at the original preparation. Exact interval validation of an earlier occupancy and recovery prefix preserves its actual energy correlations and places every admitted courier on a forward harmonic branch. Receiving onset and cutoff then occur uniquely, with cutoff before model time 139.0345 and before the next negative main-wall entry. The same actual state continues through that wall and three outgoing main waves to the unchanged fixed readout T3* = 706661551305064777/4503599627370496. At this clock the main lies in (4 ell, 5 ell) and the courier in (3 ell, 4 ell); all relevant source guards hold along the intervening path. Orthogonal free transport after each member's actual cutoff preserves its port-error norm exactly, yielding a joint error below 0.000372 against the required tolerance 0.01, with the actual previous resident retained in the reference. A complete functional map advances all 68 coordinates, including both histories, archives, routers, and paid clocks. The incremental source account contains one receiving debit and three outgoing upper-trace debits; the continuous wall adds no trace. The result retains the inherited source, membership, and preparation premises and establishes one finite supplied third service, not arbitrary repeatability. The proof combines written source analysis with reproducible exact arithmetic. A specified supporting subset of rational witnesses and abstract algebraic lemmas has been executed in Lean and its returned evidence assessed; the physical source and validated-numerics arguments remain outside that subset.