diff --git a/apps/api/src/app/seed-activities.ts b/apps/api/src/app/seed-activities.ts
index 03e9dab..c94bd7c 100644
--- a/apps/api/src/app/seed-activities.ts
+++ b/apps/api/src/app/seed-activities.ts
@@ -15,7 +15,8 @@ import { readFile } from 'node:fs/promises';
 import { join, resolve } from 'node:path';
 import { activityManifestSchema } from '@contracts';
 import type { Container } from './container.ts';
-import { MASTER_OBJECTS, MASTER_SAMPLE_ROWS } from './seed-mvp-data.ts';
+import { MASTER_DOMAINS, MASTER_OBJECTS, MASTER_SAMPLE_ROWS } from './seed-mvp-data.ts';
+import { W05_TOOLS, W05_TOOL_SAMPLE } from './tools-w05.ts';
 
 /** 已开发完成、要随播种装上的真活动包(目录名 = 包目录,不是 activityId) */
 /*
@@ -29,8 +30,9 @@ import { MASTER_OBJECTS, MASTER_SAMPLE_ROWS } from './seed-mvp-data.ts';
  * 再跑 activities:install 即可 —— 它们的 dist 照旧随 activities:build 产出。
  *   退役名单:quote-intake · quote-alternative · quote-sourcing · quote-pricing ·
  *             quote-negotiate · quote-archive
+ * 2026-08-26 加 ACT-WORK-05(part-substitution-assessment):差异评估活动开发完成,随本轮登记进安装通道。
  */
-const REAL_PACKAGES = ['crm-relationship-coverage', 'brand-content-toolkit'] as const;
+const REAL_PACKAGES = ['crm-relationship-coverage', 'brand-content-toolkit', 'part-substitution-assessment'] as const;
 
 /**
  * 活动包根目录。
@@ -61,10 +63,21 @@ export async function installRealActivities(container: Container): Promise<void>
   const applied = await container.ledger.applyDeclarations(MASTER_OBJECTS);
   const conflicts = applied.flatMap((r) => r.conflicts);
   log(
-    `   主数据四域已物化:${MASTER_OBJECTS.length} 张表` +
+    `   主数据 ${MASTER_DOMAINS.length} 域已物化:${MASTER_OBJECTS.length} 张表` +
       // 冲突要如实报:静默吞掉的话,表结构和声明对不上而没人知道
       (conflicts.length === 0 ? '' : ` —— 合并冲突 ${conflicts.length} 处:${conflicts.map((c) => c.field).join('、')}`),
   );
+
+  /*
+   * **纯工具随活动一起注册**(2026-08-26):从前工具契约只在 db:seed 里注册,只跑 activities:install 的
+   * 开发机上,活动清单声明了工具、白名单也发了,`sys.tool` 里却没有那件工具 —— 第一次跑就撞「工具不存在」。
+   * 「安装即用」包含它声明过的纯工具能调得动。register 按 name+version 幂等,重复装是 no-op。
+   */
+  for (const contract of W05_TOOLS) {
+    const verdict = await container.toolbox.register({ contract, samples: [W05_TOOL_SAMPLE] });
+    if (!verdict.accepted) log(`   工具 ${contract.name} 未过两审:${verdict.staticFindings.map((f) => f.message).join('; ')}`);
+  }
+
   const root = activitiesRoot();
 
   for (const dir of REAL_PACKAGES) {
diff --git a/tools/build-activities.ts b/tools/build-activities.ts
index 511fc07..1b1955b 100644
--- a/tools/build-activities.ts
+++ b/tools/build-activities.ts
@@ -19,6 +19,7 @@ import { manifest as quoteSourcing } from '../activities/quote-sourcing/src/mani
 import { manifest as quoteAlternative } from '../activities/quote-alternative/src/manifest.ts';
 import { manifest as crmRelationshipCoverage } from '../activities/crm-relationship-coverage/src/manifest.ts';
 import { manifest as brandContentToolkit } from '../activities/brand-content-toolkit/src/manifest.ts';
+import { manifest as partSubstitutionAssessment } from '../activities/part-substitution-assessment/src/manifest.ts';
 
 const root = dirname(dirname(fileURLToPath(import.meta.url)));
 
@@ -31,6 +32,7 @@ const PACKAGES = [
   { dir: 'quote-alternative', manifest: quoteAlternative },
   { dir: 'crm-relationship-coverage', manifest: crmRelationshipCoverage },
   { dir: 'brand-content-toolkit', manifest: brandContentToolkit },
+  { dir: 'part-substitution-assessment', manifest: partSubstitutionAssessment },
 ] as const;
 
 for (const pkg of PACKAGES) {