test(dogfood): drop the removed feature.zod expression surface from the ADR-0058 ledger

The expression-conformance ledger's cel-formula entry covered
kernel/feature.zod.ts:expression — the surface vanished with the orphaned
FeatureFlagSchema module, so the ADR-0060 checkLedger STALE-covers gate
correctly failed Dogfood shard 2/2. Caught by the ledger, not by symbol
grep: the entry references the file PATH, not the FeatureFlag symbol.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: os-zhuang

packages/qa/dogfood/test/expression-conformance.ledger.ts

@@ -80,13 +80,15 @@ export const EXPRESSION_SURFACE: ExprSurface[] = [
   },
   {
     id: 'cel-formula',
-    summary: 'computed / formula field + mapping / feature expressions',
+    summary: 'computed / formula field + mapping expressions',
     dialect: 'cel', mode: 'interpret', state: 'enforced', failPolicy: 'fail-soft-log',
     enforcement: '@objectstack/formula celEngine (interpret)',
+    // kernel/feature.zod.ts:expression was covered here until the orphaned
+    // FeatureFlagSchema module was removed (zero runtime consumers once its
+    // capabilities-descriptor home went, #3605).
     covers: [
       'data/field.zod.ts:expression',
       'shared/mapping.zod.ts:expression',
-      'kernel/feature.zod.ts:expression',
     ],
   },
   {