refactor(spec): one finding per situation in the container-coverage report (#4956)

A coordinate that is BOTH double-declared and gone was reporting twice — as a
stale row and as a contradiction. The single fix is to delete the row(s), and a
second heading about a coordinate that no longer exists obscures it. Same rule
orphans.mts already follows for its one deliberately-silent case.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ehu85kbvMcrNTUJjwxvLJ9

Author: claude

packages/spec/scripts/liveness/drill.mts

@@ -153,18 +153,22 @@ export function reconcileContainerCoverage({
   const brokenDeferrals: string[] = [];
   let deferredChildKeys = 0;
   for (const { container, to } of deferred) {
+    const here = seen.get(container);
+    // Already reported as stale. Say nothing more about it — including the
+    // both-lists contradiction below — because the single fix is to delete the
+    // row(s), and a second heading about a coordinate that no longer exists
+    // would obscure it (the `orphans.mts` rule, same reasoning).
+    if (!here) continue;
     // Declared in BOTH lists — "classified nowhere" AND "classified at `to`"
     // cannot both be true, and whichever the gate silently preferred would
-    // decide whether the keys count as a gap. Refuse instead of picking.
+    // decide whether these keys count as a gap. Refuse instead of picking.
     if (recorded.has(container)) {
       brokenDeferrals.push(
         `${container} is declared in BOTH lists — 'containers' says its child keys are classified nowhere, ` +
         `'deferred' says they are classified at '${to}'. Delete whichever is wrong.`,
       );
       continue;
     }
-    const here = seen.get(container);
-    if (!here) continue; // already reported as stale
     const target = classifiedKeysAt(to);
     if (!target) {
       brokenDeferrals.push(

packages/spec/scripts/liveness/drill.test.ts

@@ -200,14 +200,18 @@ describe('reconcileContainerCoverage — deferrals are resolved, never believed'
     expect(r.deferredChildKeys).toBe(0);
   });
 
-  it('reports a stale coordinate once even when both lists name it', () => {
+  it('reports a gone-and-double-declared coordinate ONLY as stale', () => {
+    // Both rows are wrong, but the single fix is to delete them, and a second
+    // heading about a coordinate that no longer exists would obscure that —
+    // the same "do not report it twice" rule orphans.mts follows.
     const r = reconcileContainerCoverage({
       observed: [],
       baseline: ['object/fields'],
       deferred: [{ container: 'object/fields', to: 'field' }],
       classifiedKeysAt: resolver,
     });
     expect(r.stale).toEqual(['object/fields']);
+    expect(r.brokenDeferrals).toEqual([]);
   });
 
   it('reports a deferral for a container that no longer exists as STALE, not broken', () => {