Separate region drafts from measurements and reject stale source geometry

Automatic bands now produce a non-overwriting draft, not a measured spec. Bind successful region measurements to their source bytes so failed revisions cannot advance against old geometry. Preserve prior measurements and native fidelity checks.

AI-assisted implementation and validation by Codex under maintainer direction.

tests/oracle/DELTAS.md

@@ -191,3 +191,13 @@ files, measurements, exit codes and frozen function vectors were not replaced.
 The plate gate applies reference UI exclusions symmetrically after alignment;
 regressions separately verify hidden-pixel invariance, visible missing-art
 rejection, raw comp-copy rejection and unchanged candidate-check state.
+
+## Recorded 2026-09-18: draft region authoring and source binding
+
+`comp-spec-usage` now describes --auto as a draft writer. In
+`comp-spec-regions`, the only file-content addition is regionsSource with the
+input path and fixture-derived SHA-256; all existing fields and measurements
+were compared unchanged. No frozen function vectors changed. New Rust
+regressions verify automatic drafts do not overwrite specs or existing drafts,
+cannot be submitted unchanged, and a rejected/missing region-source revision
+cannot advance the build using the last successful measurements.

tests/oracle/golden/comp-spec-usage.json

@@ -1,5 +1,5 @@
 {
-  "stdout": "REGION COORDINATES: use one of grid (coarse inclusive cells), box {x,y,w,h} (fractions of the comp, 0..1), or pixelBox {x,y,w,h} (whole pixels in the original comp). Use exact bounds when an element ends inside a grid cell; do not include neighbouring content.\nusage: comp-spec.mjs --comp <png> --grid            write .impeccable/build/comp-grid.png (10x10 labeled grid) + palette + bands\n       comp-spec.mjs --comp <png> --regions <json>  measure regions -> .impeccable/build/spec.json\n         regions json: { \"regions\": [ { \"id\": \"art\", \"kind\": \"plate|image|texture|text|control|chrome\", \"grid\": \"E0:J4\", \"note\": \"...\" } ] }\n       comp-spec.mjs --comp <png> --auto            band regions when you have no regions file\n       comp-spec.mjs --print                        the compact spec\n       comp-spec.mjs --crop <id> [--out f] [--scale n]   reference crop of a region (never a shipping asset)\n       comp-spec.mjs --plate-prompt <id> [--background transparent|opaque|auto]  the regeneration prompt for a raster region\n",
+  "stdout": "REGION COORDINATES: use one of grid (coarse inclusive cells), box {x,y,w,h} (fractions of the comp, 0..1), or pixelBox {x,y,w,h} (whole pixels in the original comp). Use exact bounds when an element ends inside a grid cell; do not include neighbouring content.\nusage: comp-spec.mjs --comp <png> --grid            write .impeccable/build/comp-grid.png (10x10 labeled grid) + palette + bands\n       comp-spec.mjs --comp <png> --regions <json>  measure regions -> .impeccable/build/spec.json\n         regions json: { \"regions\": [ { \"id\": \"art\", \"kind\": \"plate|image|texture|text|control|chrome\", \"grid\": \"E0:J4\", \"note\": \"...\" } ] }\n       comp-spec.mjs --comp <png> --auto [--out f]  write a band draft; refine into elements before --regions\n       comp-spec.mjs --print                        the compact spec\n       comp-spec.mjs --crop <id> [--out f] [--scale n]   reference crop of a region (never a shipping asset)\n       comp-spec.mjs --plate-prompt <id> [--background transparent|opaque|auto]  the regeneration prompt for a raster region\n",
   "stderr": "",
   "exit": 0,
   "signal": null,