Fix comp gate evidence and stale plate approvals

Measure declared region bounds, keep raw and effective verdicts distinct,
and use active blockers for repair feedback. Revalidate plate receipts
against current asset, region, and comp hashes; require an explicit quoted
comp-authority downgrade for force overrides.

Add regressions for missing assets, copied comp pixels, repeated failures,
generic delegation, and stale reports. Preserve fidelity thresholds.

AI assistance: implemented and validated with OpenAI Codex.

tests/oracle/DELTAS.md

@@ -164,3 +164,15 @@ installed. The binary's `CLI_VERSION` moves from `3.6.0` to `4.0.0` with the
 CLI 4.0.0 release; it is what the binary prints when run directly.
 
 - `cli-version`.
+
+## Recorded 2026-09-11: comp regions no longer include neighbouring pixels
+
+The `comp-diff-no-spec` golden now measures the automatic bands at their actual
+bounds rather than enlarging bands under 48px. Reviewed changes are confined to
+regional scores and ink boxes: the second band's overall is 0.6755 (was 0.6951),
+the fourth is 1.0 (was 0.9468), and narrow-band ink boxes use the corrected crop
+coordinates. Whole-frame scores, verdicts, region definitions, exit status, and
+stderr are unchanged. The golden was updated to enforce these exact results;
+this is not an open-ended accepted delta. Frozen function call vectors remain
+unchanged. The Rust narrow-region regression independently checks that changing
+only neighbouring pixels leaves the measured crop identical.