[JoyboyBrian]

The helper462/frame506 low_type_commit had no physical complete-payload implementation after the carry frontend. This adds a literal fixed-tape consumer that permutes all low-type blocks, preserves complete high/spectator fibers, installs the output into the original source owner and retires old-cache/private storage. Unary nested loops build the runtime fiber extent without free arithmetic or addressing.

For V=T Q^D Z and old-cache length K, the reviewed commit bound is 128(T+D+1)V+16K+16+128D transitions; visited space is (D+8)V+2K+64(D+1). Literal cache preparation adds at most5K+16 transitions. The K1000,T=D=V1 control records12,250 commit transitions, rejecting the earlier undercount.

Validation covers both directions on the complete48-type GL2(F3) domain, complete high/spectator payloads, translated origins, independent interpreters, actual S8 modular bindings and failure controls. Python3.12 normal/optimized, source-history and20-file Git-free export checks pass. Peer review additionally checked an independent random full3888-bit payload with both interpreters.

This is a scoped physical consumer, not the full physical route or a new kappa. Actual per-fiber carry/high linking, runtime descriptors, the cell0 two-OLD-swap repair, caller/cache-layout integration and P3 remain explicit obligations. Source-specific constants are finite but enormous; no practical/full-supplier admission is claimed.

Credit David Arias PR2776, Charles Bethin, the PR4989/5019 and carry frontend work, Chris R/Clear1nsight, ai-nanachi and the retained ROW/native/tape lineage. JoyboyBrian with substantial OpenAI Codex assistance; Apache-2.0. Canonical investigation: #4945 (comment)