fix(hub): mark bootstrap Inbox as SYSTEM_INBOX

Alpha silo bootstrap created the root Inbox without kind=SYSTEM_INBOX, so
Feishu card project creation tried to insert a second Inbox and hit the
sibling-name unique index. Tag the bootstrap folder correctly and promote
any legacy root Inbox on ensure.

hub/test/integration/project-onboarding.test.ts

@@ -101,6 +101,43 @@ describe("ADR-0021 project onboarding", () => {
     ]));
   });
 
+  it("promotes a legacy root Inbox when Feishu chat creates a project", async () => {
+    await seedUser("u-member", "ou_member", "MEMBER");
+    // Production drift after bootstrap omitted kind=SYSTEM_INBOX. The protect
+    // trigger refuses demotion, so the test plants the legacy shape directly.
+    await prisma.$executeRawUnsafe(`ALTER TABLE "Folder" DISABLE TRIGGER cph_protect_system_inbox`);
+    try {
+      await prisma.folder.updateMany({
+        where: { organizationId: DEFAULT_ORG_ID, kind: "SYSTEM_INBOX", archivedAt: null },
+        data: { kind: "REGULAR" },
+      });
+    } finally {
+      await prisma.$executeRawUnsafe(`ALTER TABLE "Folder" ENABLE TRIGGER cph_protect_system_inbox`);
+    }
+    const legacy = await prisma.folder.findFirstOrThrow({
+      where: { organizationId: DEFAULT_ORG_ID, parentId: null, name: "Inbox", archivedAt: null },
+      select: { id: true, kind: true },
+    });
+    expect(legacy.kind).toBe("REGULAR");
+
+    const result = await createProjectFromFeishuChat(prisma, {
+      organizationId: DEFAULT_ORG_ID,
+      actorFeishuOpenId: "ou_member",
+      chatId: "chat-legacy-inbox",
+      name: "Recovered Inbox Project",
+      workspaceRoot: await tempWorkspaceRoot(),
+    });
+
+    expect(result.folderId).toBe(legacy.id);
+    await expect(prisma.folder.findUniqueOrThrow({
+      where: { id: legacy.id },
+      select: { kind: true },
+    })).resolves.toEqual({ kind: "SYSTEM_INBOX" });
+    expect(await prisma.folder.count({
+      where: { organizationId: DEFAULT_ORG_ID, name: "Inbox", archivedAt: null },
+    })).toBe(1);
+  });
+
   it("blocks ordinary Feishu project creation when the org setting is off", async () => {
     await seedUser("u-member", "ou_member", "MEMBER");
     await setMembersCanCreateProjects(prisma, {

hub/test/integration/silo-bootstrap.test.ts

@@ -62,6 +62,11 @@ describe("Alpha Silo bootstrap", () => {
       { roleId: "draft", label: "草稿", isDefault: true },
       { roleId: "review", label: "审校", isDefault: false },
     ]);
+    await expect(prisma.folder.findMany({
+      where: { organizationId: "org_alpha", archivedAt: null },
+      select: { name: true, kind: true, parentId: true },
+    })).resolves.toEqual([{ name: "Inbox", kind: "SYSTEM_INBOX", parentId: null }]);
+
 
     const persisted = JSON.stringify({
       feishu: await prisma.feishuApplicationCredentialVersion.findMany(),