hzcheng · hzcheng · Aug 19, 2026 · Aug 19, 2026 · Aug 19, 2026
diff --git a/docs/testing/main-capability-coverage.json b/docs/testing/main-capability-coverage.json
@@ -2,7 +2,7 @@
     "version": 1,
     "audit": {
         "base": "2b34c653119bdf480f2af0330ee3809b51441807",
-        "head": "0accf78e1919556c57dd08a4d055bc5bfa6419ae",
+        "head": "66fbdbcf0e6b9d26768ce432fe0e0a49dad2e8db",
         "ignoredDocumentationCommits": [
             "dd86a325e3db5aa013ffa18a647e67e9fa279c10",
             "0b0e12b4d97ec7d77a8a93076459fdaad2e52070",
@@ -478,7 +478,8 @@
             "4cf025e589a2f7426ae1f68d40c774429b6b9855",
             "8aeef7b953132be14677977d21d41ffe1e051dd0",
             "6cc7fca077b4929411d6dbaede79e8e560346ece",
-            "2cc5b47de6e8fe51b4998293b0dc224ea908fdf3"
+            "2cc5b47de6e8fe51b4998293b0dc224ea908fdf3",
+            "37027f5c598f916c0656343248fb059be7ab8daf"
         ]
     },
     "capabilities": [
@@ -2356,7 +2357,8 @@
                 "630595db25f3f3723c85aa863de001982a1f6aaa",
                 "86a597dbe65633fd3328534788890febeb1644fd",
                 "4b3d7e25531865cbdd203830e71c964a57207de8",
-                "0accf78e1919556c57dd08a4d055bc5bfa6419ae"
+                "0accf78e1919556c57dd08a4d055bc5bfa6419ae",
+                "66fbdbcf0e6b9d26768ce432fe0e0a49dad2e8db"
             ],
             "behaviors": [
                 "ARCH-POLICY-SCHEMA-001",

diff --git a/package.json b/package.json
@@ -612,7 +612,7 @@
         "test:conversation-performance": "node scripts/run-conversation-performance-checks.js",
         "test:conversation-sources:remote": "node --test tests/platform/remote/conversationSources.test.js",
         "test:extension-host": "npm run package:release && node scripts/run-extension-host-tests.js",
-        "test:ci:linux": "npm run test-compile && npm run brand:verify && npm run brand:check && npm run test:behavior-contracts && npm run lint:ci && npm run test:coverage:run && npm run test:conversation-sources:remote && npm run test:conversation-performance && npm run test:browser:run && npm run test:safety:run && npm run test:dashboard:run && npm run test:architecture-baseline && npm run test:architecture-guards && npm run test:architecture-policy && node scripts/run-guard-mutation-parity.js && npm run test:release-notes && npm run test:release-packaging && node scripts/check-coverage-baseline.js && node scripts/check-changed-coverage.js",
+        "test:ci:linux": "npm run test-compile && npm run brand:verify && npm run brand:check && npm run test:behavior-contracts && npm run lint:ci && npm run test:coverage:run && npm run test:conversation-sources:remote && npm run test:conversation-performance && npm run test:browser:run && npm run test:safety:run && npm run test:dashboard:run && npm run test:architecture-baseline && npm run test:architecture-guards && npm run test:architecture-policy && npm run test:release-notes && npm run test:release-packaging && node scripts/check-coverage-baseline.js && node scripts/check-changed-coverage.js",
         "brand:check": "node scripts/check-brand-identity.js",
         "brand:generate": "node scripts/generate-brand-assets.js",
         "brand:verify": "node scripts/generate-brand-assets.js --check",

diff --git a/scripts/architecture/architectureChangeRecords.js b/scripts/architecture/architectureChangeRecords.js
@@ -44,7 +44,7 @@ const BLOCK_PATTERN = /```arch-change\s*\r?\n([\s\S]*?)```/;
 
 const DELTA_MAP_KEYS = ['mayDependOnGrown', 'entrypointsGrown'];
 const DELTA_LIST_KEYS = ['baselineGrown', 'waiversAdded', 'ledgerRegressions'];
-const DELTA_FLAG_KEYS = ['rePartition', 'harnessWeakening', 'guardSemantics'];
+const DELTA_FLAG_KEYS = ['rePartition', 'harnessWeakening'];
 const DELTA_KEYS = [...DELTA_MAP_KEYS, ...DELTA_LIST_KEYS, ...DELTA_FLAG_KEYS,
     'invariantChanges', 'fileMoves'];
 
@@ -213,7 +213,6 @@ function parseArchitectureChangeRecord({ path: recordPath, text }) {
         fileMoves: rawDelta.fileMoves || [],
         rePartition: rawDelta.rePartition === true,
         harnessWeakening: rawDelta.harnessWeakening === true,
-        guardSemantics: rawDelta.guardSemantics === true,
     };
     return {
         record: {

diff --git a/scripts/architecture/checkArchitectureChange.js b/scripts/architecture/checkArchitectureChange.js
@@ -1,54 +1,23 @@
 'use strict';
 
 /**
- * Anti-self-amendment gate (Harness v0, program Stage 2 PR 4; charter 8.9).
+ * Anti-self-amendment gate (Harness Simplification PR #296).
  *
  * Classifies a change by its impact on protected architecture policy and the
- * harness surface (review R2):
- * - product-only: neither policy files nor the harness surface touched;
- * - tightening: policy only narrows, or the harness surface changes without
- *   weakening;
- * - relaxing or registry re-partition: baseline grew, waivers added,
- *   mayDependOn broadened, writer sets grew, module structure changed, or
- *   the harness surface weakened (a guard file deleted, a guard id removed,
- *   a lane or workflow invocation removed, mutation tests shrank).
+ * harness surface. Relaxing or re-partition changes require owner architecture
+ * approval (approve-architecture <sha>), enforced by the trusted kernel.
  *
- * A relaxing or re-partition change is authorized in one of two ways:
- *
- * 1. Owner architecture approval (Harness Simplification decision,
- *    docs/architecture/harness-simplification-decision.md): the repository
- *    owner comments `approve-architecture <full-head-sha>` on the PR. The
- *    approval binds the exact head and expires when the head moves. This is
- *    the transitional replacement for machine authorization and the only
- *    path once Architecture Change records become historical ADRs.
- * 2. An Architecture Change record that already exists in the PR base
- *    (review R3; charter 8.9: the record lands in its own earlier PR before
- *    product work consumes it). The record must carry a valid ```arch-change
- *    machine-summary block whose declared delta covers the actual policy
- *    delta; an empty markdown file, a bare filename match, or a record added
- *    in the same PR never authorizes. Because every merge requires the
- *    merge-approval status (owner comment newer than the PR head), a record
- *    present in the base was necessarily approved after its final commit —
- *    approval timing holds transitively.
- *
- * An agent cannot legalize its own violation: the classification is computed
- * from the diff, not declared, and both authorization paths live outside the
- * PR head (owner comment on the PR, record in the base).
+ * Architecture Change records are historical ADRs only — no machine
+ * authorization, no record consumption, no parity exemption.
  */
 
 const path = require('path');
 const {
     collectArchitectureDiff,
     defaultGit,
 } = require('./reportArchitectureDiff');
-const {
-    ARCH_CHANGE_RECORD_PATTERN,
-    coversPolicyDelta,
-    fingerprintFields,
-    parseArchitectureChangeRecord,
-} = require('./architectureChangeRecords');
+const { ARCH_CHANGE_RECORD_PATTERN } = require('./architectureChangeRecords');
 
-// Kept for backward compatibility with existing imports.
 const ARCH_CHANGE_PATTERN = ARCH_CHANGE_RECORD_PATTERN;
 
 function harnessWeakenedOf(harness) {
@@ -58,118 +27,6 @@ function harnessWeakenedOf(harness) {
         || harness.shrunkMutationTests.length > 0;
 }
 
-/**
- * The exact delta a consuming change realizes — the shape a record must
- * declare verbatim (round-2 review Blocker 3). Shared by the gate (coverage
- * matching) and scripts/architecture/describeArchitectureChange.js
- * (record authoring).
- */
-function computeActualDelta(report, classification, harnessWeakened) {
-    const delta = report.policyDelta;
-    const invariantChanges = Object.entries(delta.invariantChanges || {})
-        .map(([id, change]) => ({ id, ...change }));
-    const isTighteningOnly = change =>
-        change.fields.length === 1 && change.fields[0] === 'writers'
-        && (change.writersAdded || []).length === 0;
-    const relaxingInvariantChanges = invariantChanges.filter(change => !isTighteningOnly(change));
-    // Removed invariants join the coverage surface with a removal marker:
-    // the record must declare the exact removed record's fingerprint.
-    const removedEntries = (delta.invariantsRemoved || []).map(id => ({
-        id,
-        fields: ['removed'],
-        before: fingerprintFields({ record: (report.removedInvariantRecords || {})[id] }),
-        after: fingerprintFields({}),
-    }));
-    // Round-2 review Blocker 3: the record's module scope must cover every
-    // module the change actually touches.
-    const touchedModules = new Set(Object.keys(report.touchedModules || {}));
-    for (const key of Object.keys(delta.mayDependOnGrown || {})) { touchedModules.add(key); }
-    for (const key of Object.keys(delta.entrypointsGrown || {})) { touchedModules.add(key); }
-    for (const move of report.moduleMoves || []) {
-        touchedModules.add(move.from);
-        touchedModules.add(move.to);
-    }
-    for (const regression of delta.ledgerRegressions || []) {
-        touchedModules.add(regression.split(':')[0]);
-    }
-    for (const moduleId of report.changedInvariantModules || []) { touchedModules.add(moduleId); }
-    return {
-        policyDelta: delta,
-        harnessWeakened,
-        rePartition: classification === 're-partition',
-        invariantChanges: [...relaxingInvariantChanges, ...removedEntries].map(
-            ({ id, fields, before, after }) => ({ id, fields, before, after })),
-        fileMoves: report.moduleMoves || [],
-        touchedModules: [...touchedModules].sort(),
-    };
-}
-
-/**
- * Authorize a relaxing/re-partition classification against the Architecture
- * Change records present in the base. Returns the error list (empty when
- * authorized).
- */
-function authorizeWithBaseRecords(report, classification, harnessWeakened, options) {
-    const baseRecords = report.baseRecords || [];
-    const architectureApproved = Boolean(options && options.architectureApproved);
-    const candidates = [];
-    const invalid = [];
-    for (const { path: recordPath, text } of baseRecords) {
-        const { record, errors } = parseArchitectureChangeRecord({ path: recordPath, text });
-        if (record) { candidates.push(record); }
-        if (errors.length > 0) { invalid.push(...errors); }
-    }
-    const actual = computeActualDelta(report, classification, harnessWeakened);
-    let bestMissing = null;
-    for (const record of candidates) {
-        const { covered, missing } = coversPolicyDelta(record, actual);
-        if (covered) { return []; }
-        if (bestMissing === null || missing.length < bestMissing.length) {
-            bestMissing = missing;
-        }
-    }
-
-    const verb = classification === 'relaxing' ? 'relaxes' : 're-partitions';
-    const errors = [];
-    if (architectureApproved) {
-        // Owner architecture approval (approve-architecture <full-head-sha>)
-        // authorizes the relaxation; the approval is verified by the caller
-        // against the exact head SHA and never by PR-head content.
-        return errors;
-    }
-    if (candidates.length === 0) {
-        errors.push(`anti-self-amendment: this change ${verb} architecture policy or weakens the `
-            + 'harness, and no valid approved Architecture Change record exists in the PR base '
-            + `(found ${baseRecords.length} record file(s), ${invalid.length} invalid). Owner `
-            + 'architecture approval required — comment '
-            + '\'approve-architecture <full-head-sha>\' on the pull request; alternatively land a '
-            + 'docs-only PR adding docs/architecture/changes/ARCH-CHANGE-<seq>.md with an '
-            + '```arch-change machine-summary block (id, status "approved", modules, declared '
-            + 'delta) first; a record added in the same PR never authorizes consumption.');
-    } else {
-        errors.push(`anti-self-amendment: this change ${verb} architecture policy or weakens the `
-            + `harness beyond every approved Architecture Change record in the PR base. Uncovered `
-            + `delta: ${bestMissing.join('; ')}. Owner architecture approval required — comment `
-            + '\'approve-architecture <full-head-sha>\' on the pull request; alternatively land a '
-            + 'docs-only record PR declaring this delta first, or narrow the change to what an '
-            + 'existing record declares.');
-    }
-    if (report.newFiles.some(file => ARCH_CHANGE_RECORD_PATTERN.test(file))) {
-        errors.push('anti-self-amendment: this PR adds an Architecture Change record and consumes '
-            + 'a relaxation in the same diff — the record must land in an earlier PR (charter 8.9).');
-    }
-    return errors;
-}
-
-/**
- * classifyArchitectureChange(report, options) -> {
- *   classification: 'product-only' | 'tightening' | 'relaxing' | 're-partition',
- *   errors: string[]
- * }
- * options.architectureApproved: the owner has bound an architecture approval
- * comment to the exact head SHA (verified by the caller, never by PR-head
- * content).
- */
 function classifyArchitectureChange(report, options) {
     const errors = [];
     if (report.errors && report.errors.length > 0) {
@@ -188,9 +45,6 @@ function classifyArchitectureChange(report, options) {
     const grownMayDependOn = Object.keys(delta.mayDependOnGrown).length > 0;
     const grownEntrypoints = Object.keys(delta.entrypointsGrown || {}).length > 0;
     const ledgerRegressions = (delta.ledgerRegressions || []);
-    // Review R9 (Important 4): only a pure writer removal with an unchanged
-    // authority is tightening — an invariant change whose only edited field is
-    // `writers` with removals alone. Everything else is relaxing.
     const isTighteningOnly = change =>
         change.fields.length === 1 && change.fields[0] === 'writers'
         && (change.writersAdded || []).length === 0;
@@ -213,9 +67,21 @@ function classifyArchitectureChange(report, options) {
     if (!relaxing && !rePartition) {
         return { classification: 'tightening', errors };
     }
-    const classification = relaxing ? 'relaxing' : 're-partition';
-    errors.push(...authorizeWithBaseRecords(report, classification, harnessWeakened, options));
-    return { classification, errors };
+
+    // Owner architecture approval (approve-architecture <full-head-sha>) is
+    // the only authorization left after record machine authorization was
+    // deleted. The caller verifies the comment binds the exact head SHA;
+    // the classifier only receives the verdict.
+    if (!(options && options.architectureApproved)) {
+        const verb = relaxing ? 'relaxes' : 're-partitions';
+        errors.push(
+            `anti-self-amendment: this change ${verb} architecture policy. `
+            + 'Owner architecture approval required — comment '
+            + '\'approve-architecture <full-head-sha>\' on the pull request.'
+        );
+    }
+
+    return { classification: relaxing ? 'relaxing' : 're-partition', errors };
 }
 
 function runArchitectureChangeCheck(rootDirectory, baseRef, options) {
@@ -239,7 +105,7 @@ function main() {
         path.resolve(__dirname, '..', '..'), undefined, { architectureApproved });
     if (errors.length > 0) {
         console.error(`Architecture change gate FAILED (classification: ${classification}):`);
-        for (const error of errors) { console.error(`  ✗ ${error}`); }
+        for (const error of errors) console.error(`  ✗ ${error}`);
         process.exitCode = 1;
         return;
     }
@@ -251,6 +117,5 @@ if (require.main === module) { main(); }
 module.exports = {
     ARCH_CHANGE_PATTERN,
     classifyArchitectureChange,
-    computeActualDelta,
     runArchitectureChangeCheck,
 };
diff --git a/scripts/architecture/describeArchitectureChange.js b/scripts/architecture/describeArchitectureChange.js
@@ -2,14 +2,10 @@
 'use strict';
 
 /**
- * Record-authoring helper (round-2 review Blocker 3): prints the exact
- * record-ready `delta` object for the current branch diff, including
- * before/after fingerprints for invariant changes and per-file module moves.
+ * Architecture diff reporter (Harness Simplification PR #296).
  *
- * Authoring flow (charter 8.9): make the policy edit locally, run this
- * script, paste the printed delta into the ARCH-CHANGE record's
- * machine-summary block, revert the edit, land the docs-only record PR, then
- * re-apply the edit in the consuming PR — the gate requires exact equality.
+ * Prints the architecture diff for the current branch. No longer generates
+ * record-ready deltas — Architecture Change records are historical ADRs.
  *
  * Usage: node scripts/architecture/describeArchitectureChange.js [base-ref]
  */
@@ -19,10 +15,7 @@ const {
     collectArchitectureDiff,
     defaultGit,
 } = require('./reportArchitectureDiff');
-const {
-    classifyArchitectureChange,
-    computeActualDelta,
-} = require('./checkArchitectureChange');
+const { classifyArchitectureChange } = require('./checkArchitectureChange');
 
 function describeArchitectureChange(rootDirectory, baseRef) {
     const report = collectArchitectureDiff({
@@ -33,33 +26,19 @@ function describeArchitectureChange(rootDirectory, baseRef) {
         git: defaultGit(rootDirectory),
     });
     const { classification } = classifyArchitectureChange(report);
-    const harness = report.harnessDelta || {};
-    const harnessWeakened = (harness.deletedFiles || []).length > 0
-        || (harness.removedGuardIds || []).length > 0
-        || (harness.removedInvocations || []).length > 0
-        || (harness.shrunkMutationTests || []).length > 0;
-    const actual = computeActualDelta(report, classification, harnessWeakened);
-    const delta = {
-        mayDependOnGrown: actual.policyDelta.mayDependOnGrown,
-        entrypointsGrown: actual.policyDelta.entrypointsGrown || {},
-        baselineGrown: actual.policyDelta.baselineGrown,
-        waiversAdded: actual.policyDelta.waiversAdded,
-        ledgerRegressions: actual.policyDelta.ledgerRegressions || [],
-        invariantChanges: actual.invariantChanges,
-        fileMoves: actual.fileMoves,
-        rePartition: actual.rePartition,
-        harnessWeakening: actual.harnessWeakened,
+    return {
+        classification,
+        policyDelta: report.policyDelta,
+        protectedTouched: report.protectedTouched,
+        harnessTouched: (report.harnessDelta || {}).touched || [],
+        touchedModules: Object.keys(report.touchedModules || {}),
     };
-    return { classification, delta, touchedModules: actual.touchedModules };
 }
 
 function main() {
-    const { classification, delta, touchedModules } = describeArchitectureChange(
-        path.resolve(__dirname, '..', '..'), process.argv[2]);
-    console.log(`classification: ${classification}`);
-    console.log(`modules: ${JSON.stringify(touchedModules)}`);
-    console.log('delta for the record machine-summary block:');
-    console.log(JSON.stringify(delta, null, 2));
+    const root = path.resolve(__dirname, '..', '..');
+    const result = describeArchitectureChange(root, process.argv[2]);
+    console.log(JSON.stringify(result, null, 2));
 }
 
 if (require.main === module) { main(); }

diff --git a/scripts/architecture/trustedKernel.js b/scripts/architecture/trustedKernel.js
@@ -301,7 +301,6 @@ const PROTECTED_PATHS = [
     'tests/unit/architecture-parity/',
     '.github/workflows/',
     'scripts/run-architecture-guards.js',
-    'scripts/run-guard-mutation-parity.js',
     'scripts/run-merge-approval-gate.js',
     'scripts/lib/mergeApprovals.js',
     'scripts/lib/ciContracts.js',

diff --git a/scripts/run-architecture-approval-gate.js b/scripts/run-architecture-approval-gate.js
@@ -16,7 +16,6 @@ const PROTECTED_PATHS = [
     'tests/unit/architecture-parity/',
     '.github/workflows/',
     'scripts/run-architecture-guards.js',
-    'scripts/run-guard-mutation-parity.js',
     'scripts/run-merge-approval-gate.js',
     'scripts/lib/mergeApprovals.js',
     'scripts/lib/ciContracts.js',