diff --git a/lib/content/lifecycle.test.ts b/lib/content/lifecycle.test.ts
new file mode 100644
index 0000000..c3e0cdd
--- /dev/null
+++ b/lib/content/lifecycle.test.ts
@@ -0,0 +1,379 @@
+import { describe, expect, it } from "vitest";
+
+import { ContentLifecycle } from "./lifecycle";
+
+const characterId = "17d23f26-df04-47e5-b8da-907d62b15260";
+const pageId = "432cf444-dd8a-4ee5-8b21-6dc6d5d325e7";
+const secondPageId = "9e52ac3a-b3fe-431b-adb6-d9cae2798705";
+const sourceId = "33a89cab-d063-4551-9b13-5b3eb6ab6e61";
+const mediaId = "cb661013-c489-4da0-8b1f-f7afcb327dd6";
+const authorId = "admin";
+
+function setup(now = new Date("2026-08-28T10:15:00.000Z")) {
+  let sequence = 0;
+  const store = new ContentLifecycle({
+    now: () => new Date(now),
+    idFactory: () =>
+      `00000000-0000-4000-8000-${String(++sequence).padStart(12, "0")}`,
+  });
+  store.addCharacter({
+    id: characterId,
+    slug: "mizuki",
+    nameTh: "มิซึกิ",
+    nameEn: "Mizuki",
+    description: null,
+    portraitMediaId: null,
+    element: "ลม",
+    role: "สนับสนุน",
+    rarity: 5,
+    sortOrder: 0,
+  });
+  store.addDataSource({
+    id: sourceId,
+    name: "อาวุธ",
+    version: 1,
+    fields: [
+      { key: "name", label: "ชื่อ", type: "text" },
+      { key: "base", label: "พื้นฐาน", type: "number" },
+      { key: "bonus", label: "โบนัส", type: "number" },
+      {
+        key: "score",
+        label: "คะแนน",
+        type: "number",
+        formula: "base + bonus",
+      },
+    ],
+    rows: [
+      {
+        id: "06200523-1a7b-478c-8587-c54483458dac",
+        values: { name: "ตัวเลือก A", base: "10", bonus: "2", score: null },
+      },
+    ],
+  });
+  store.addPage({
+    id: pageId,
+    characterId,
+    slug: "info",
+    title: "ข้อมูล",
+    navOrder: 1,
+    publicNote: null,
+  });
+  store.addPage({
+    id: secondPageId,
+    characterId,
+    slug: "combo",
+    title: "คอมโบ",
+    navOrder: 0,
+    publicNote: null,
+  });
+  return store;
+}
+
+function rankingBlock() {
+  return {
+    id: "1e0b3229-549c-4897-a765-50c56d26b414",
+    type: "ranking",
+    schemaVersion: 1,
+    sortOrder: 0,
+    config: {
+      title: "อันดับอาวุธ",
+      dataSourceId: sourceId,
+      labelField: "name",
+      valueField: "score",
+      higherIsBetter: true,
+    },
+  };
+}
+
+describe("content lifecycle", () => {
+  it("starts new content hidden and requires both visibility flags", () => {
+    const store = setup();
+    expect(store.getDirectory()).toEqual([]);
+
+    store.setCharacterVisibility(characterId, true);
+    expect(store.getDirectory()).toEqual([]);
+
+    const saved = store.savePage({
+      pageId,
+      expectedVersion: 1,
+      authorId,
+      title: "ข้อมูล",
+      slug: "info",
+      visible: true,
+      publicNote: "อัปเดตล่าสุดสำหรับเวอร์ชัน 1.0",
+      blocks: [rankingBlock()],
+    });
+    expect(saved.status).toBe("accepted");
+    expect(store.getDirectory()).toMatchObject([
+      { slug: "mizuki", firstPageSlug: "info" },
+    ]);
+    expect(store.resolvePublicRoute("mizuki", "info")).toMatchObject({
+      type: "page",
+      snapshot: { page: { publicNote: "อัปเดตล่าสุดสำหรับเวอร์ชัน 1.0" } },
+    });
+  });
+
+  it("orders pages and redirects a character route to the first visible page", () => {
+    const store = setup();
+    store.setCharacterVisibility(characterId, true);
+    store.savePage({
+      pageId,
+      expectedVersion: 1,
+      authorId,
+      title: "ข้อมูล",
+      slug: "info",
+      visible: true,
+      blocks: [],
+    });
+    store.savePage({
+      pageId: secondPageId,
+      expectedVersion: 1,
+      authorId,
+      title: "คอมโบ",
+      slug: "combo",
+      visible: true,
+      blocks: [],
+    });
+
+    expect(store.resolvePublicRoute("mizuki")).toEqual({
+      type: "redirect",
+      location: "/mizuki/combo",
+      status: 308,
+    });
+  });
+
+  it("creates permanent aliases after custom character and page slug changes", () => {
+    const store = setup();
+    store.setCharacterVisibility(characterId, true);
+    store.savePage({
+      pageId,
+      expectedVersion: 1,
+      authorId,
+      title: "ข้อมูล",
+      slug: "build-info",
+      visible: true,
+      blocks: [],
+    });
+
+    expect(store.resolvePublicRoute("mizuki", "info")).toEqual({
+      type: "redirect",
+      location: "/mizuki/build-info",
+      status: 308,
+    });
+    store.renameCharacter(characterId, "mizuki-guide");
+    expect(store.resolvePublicRoute("mizuki", "build-info")).toEqual({
+      type: "redirect",
+      location: "/mizuki-guide/build-info",
+      status: 308,
+    });
+  });
+
+  it("rejects stale concurrent changes and invalid blocks", () => {
+    const store = setup();
+    const accepted = store.savePage({
+      pageId,
+      expectedVersion: 1,
+      authorId,
+      title: "ข้อมูลใหม่",
+      slug: "info",
+      visible: false,
+      blocks: [],
+    });
+    expect(accepted.status).toBe("accepted");
+    expect(
+      store.savePage({
+        pageId,
+        expectedVersion: 1,
+        authorId,
+        title: "เขียนทับ",
+        slug: "info",
+        visible: false,
+        blocks: [],
+      }),
+    ).toEqual({ status: "conflict", currentVersion: 2 });
+    expect(
+      store.savePage({
+        pageId,
+        expectedVersion: 2,
+        authorId,
+        title: "ข้อมูลใหม่",
+        slug: "info",
+        visible: false,
+        blocks: [
+          {
+            id: "c9c1fc08-8180-439b-8962-26fe1c8977b1",
+            type: "callout",
+            schemaVersion: 1,
+            sortOrder: 0,
+            config: { body: "", tone: "unknown" },
+          },
+        ],
+      }).status,
+    ).toBe("validation-error");
+  });
+
+  it("versions global sources independently and refreshes only latest consumers", () => {
+    const store = setup();
+    const saved = store.savePage({
+      pageId,
+      expectedVersion: 1,
+      authorId,
+      title: "ข้อมูล",
+      slug: "info",
+      visible: false,
+      blocks: [rankingBlock()],
+    });
+    expect(saved.status).toBe("accepted");
+    const beforeEvents = store.getOutbox().length;
+
+    const source = store.saveDataSource({
+      id: sourceId,
+      expectedVersion: 1,
+      name: "อาวุธ",
+      fields: [
+        { key: "value", label: "ค่า", type: "number" },
+        {
+          key: "broken",
+          label: "สูตรที่ผิด",
+          type: "number",
+          formula: "value / 0",
+        },
+      ],
+      rows: [
+        {
+          id: "560bb5b4-f4c7-46ba-82d5-e3dca8217b0a",
+          values: { value: "4", broken: null },
+        },
+      ],
+    });
+    expect(source.status).toBe("accepted");
+    expect(store.getOutbox().slice(beforeEvents)).toMatchObject([
+      { eventType: "data-source.updated", payload: { version: 2 } },
+      { eventType: "page.updated", aggregateId: pageId },
+    ]);
+  });
+
+  it("coalesces hourly checkpoints, keeps named revisions, and expires only checkpoints", () => {
+    const store = setup();
+    store.savePage({
+      pageId,
+      expectedVersion: 1,
+      authorId,
+      title: "ครั้งที่ 1",
+      slug: "info",
+      visible: false,
+      blocks: [],
+      now: new Date("2026-08-28T10:05:00.000Z"),
+    });
+    store.createNamedRevision(
+      pageId,
+      "เวอร์ชันเปิดตัว",
+      authorId,
+      new Date("2026-08-28T10:10:00.000Z"),
+    );
+    store.savePage({
+      pageId,
+      expectedVersion: 2,
+      authorId,
+      title: "ครั้งที่ 2",
+      slug: "info",
+      visible: false,
+      blocks: [],
+      now: new Date("2026-08-28T10:55:00.000Z"),
+    });
+
+    expect(store.listRevisions(pageId)).toHaveLength(2);
+    expect(
+      store.listRevisions(pageId).filter((revision) => revision.kind === "checkpoint"),
+    ).toHaveLength(1);
+    const expired = store.expireCheckpoints(
+      new Date("2026-09-28T11:00:00.000Z"),
+    );
+    expect(expired).toHaveLength(1);
+    expect(store.listRevisions(pageId)).toMatchObject([
+      { kind: "named", label: "เวอร์ชันเปิดตัว", expiresAt: null },
+    ]);
+  });
+
+  it("restores a new page version pinned to historical data and can use latest again", () => {
+    const store = setup();
+    store.savePage({
+      pageId,
+      expectedVersion: 1,
+      authorId,
+      title: "เวอร์ชันเดิม",
+      slug: "info",
+      visible: false,
+      blocks: [rankingBlock()],
+    });
+    const revision = store.createNamedRevision(pageId, "ก่อนปรับสูตร", authorId)!;
+    store.saveDataSource({
+      id: sourceId,
+      expectedVersion: 1,
+      name: "อาวุธรุ่นใหม่",
+      fields: [{ key: "value", label: "ค่า", type: "number" }],
+      rows: [],
+    });
+    store.savePage({
+      pageId,
+      expectedVersion: 2,
+      authorId,
+      title: "เวอร์ชันใหม่",
+      slug: "info",
+      visible: false,
+      blocks: [rankingBlock()],
+    });
+
+    const restored = store.restoreRevision(revision.id, 3, authorId);
+    expect(restored.status).toBe("accepted");
+    if (restored.status === "accepted") {
+      expect(restored.value.page.version).toBe(4);
+      expect(restored.value.page.title).toBe("เวอร์ชันเดิม");
+      expect(restored.value.versionVector[sourceId]).toBe(1);
+    }
+
+    const latest = store.useLatestDataSource(pageId, sourceId, 4, authorId);
+    expect(latest.status).toBe("accepted");
+    if (latest.status === "accepted") {
+      expect(latest.value.page.version).toBe(5);
+      expect(latest.value.versionVector[sourceId]).toBe(2);
+    }
+  });
+
+  it("retains media for current content or revisions and exposes it only from visible snapshots", () => {
+    const store = setup();
+    store.setCharacterVisibility(characterId, true);
+    const imageBlock = {
+      id: "949499c7-3162-4ff5-87f0-f90711a97e6f",
+      type: "image",
+      schemaVersion: 1,
+      sortOrder: 0,
+      config: { mediaId, alt: "ภาพตัวอย่าง", fit: "cover" },
+    };
+    store.savePage({
+      pageId,
+      expectedVersion: 1,
+      authorId,
+      title: "ข้อมูล",
+      slug: "info",
+      visible: true,
+      blocks: [imageBlock],
+    });
+    store.createNamedRevision(pageId, "มีภาพ", authorId);
+
+    expect(store.isMediaPublic(mediaId)).toBe(true);
+    expect(store.isMediaRetained(mediaId)).toBe(true);
+
+    store.savePage({
+      pageId,
+      expectedVersion: 2,
+      authorId,
+      title: "ข้อมูล",
+      slug: "info",
+      visible: true,
+      blocks: [],
+    });
+    expect(store.isMediaPublic(mediaId)).toBe(false);
+    expect(store.isMediaRetained(mediaId)).toBe(true);
+  });
+});
diff --git a/lib/content/lifecycle.ts b/lib/content/lifecycle.ts
new file mode 100644
index 0000000..aba0136
--- /dev/null
+++ b/lib/content/lifecycle.ts
@@ -0,0 +1,764 @@
+import { z } from "zod";
+
+import { validatePageBlocks, type SerializedBlock } from "@/lib/blocks";
+
+import { dataSourceSnapshotSchema, evaluateDataSource } from "./data-source";
+import type {
+  CharacterIdentity,
+  DataSourceSnapshot,
+  PageIdentity,
+  PageSnapshot,
+  PublicCharacterCard,
+} from "./types";
+
+const checkpointRetentionMs = 30 * 24 * 60 * 60 * 1_000;
+
+export const slugSchema = z
+  .string()
+  .trim()
+  .min(1)
+  .max(120)
+  .regex(
+    /^[\p{L}\p{N}]+(?:-[\p{L}\p{N}]+)*$/u,
+    "Slugs may contain letters, numbers, and single hyphens between words.",
+  );
+
+interface StoredPage extends PageIdentity {
+  blocks: SerializedBlock[];
+  dependencies: Record<string, number | null>;
+}
+
+interface StoredDataSource {
+  id: string;
+  name: string;
+  fields: DataSourceSnapshot["fields"];
+  currentVersion: number;
+  versions: Map<number, DataSourceSnapshot>;
+}
+
+export interface ContentRevision {
+  id: string;
+  pageId: string;
+  pageVersion: number;
+  kind: "checkpoint" | "named";
+  label: string | null;
+  authorId: string;
+  sourceRevisionId: string | null;
+  checkpointHour: string | null;
+  snapshot: {
+    page: PageIdentity;
+    blocks: SerializedBlock[];
+    dependencies: Record<string, number | null>;
+  };
+  dataSourceVersions: Record<string, number>;
+  mediaIds: string[];
+  createdAt: Date;
+  expiresAt: Date | null;
+}
+
+export interface DomainOutboxEvent {
+  id: number;
+  topic: string;
+  aggregateId: string;
+  eventType:
+    | "page.updated"
+    | "directory.updated"
+    | "data-source.updated"
+    | "admin.updated";
+  payload: { id: string; version: number };
+  status: "pending" | "processed";
+  attempts: number;
+  availableAt: Date;
+  createdAt: Date;
+}
+
+interface CharacterAlias {
+  oldSlug: string;
+  characterId: string;
+}
+
+interface PageAlias {
+  oldCharacterSlug: string;
+  oldPageSlug: string;
+  pageId: string;
+}
+
+export interface SavePageInput {
+  pageId: string;
+  expectedVersion: number;
+  authorId: string;
+  title: string;
+  slug: string;
+  visible: boolean;
+  publicNote?: string | null;
+  blocks: SerializedBlock[];
+  now?: Date;
+}
+
+export type MutationResult<T> =
+  | { status: "accepted"; value: T }
+  | { status: "conflict"; currentVersion: number }
+  | { status: "validation-error"; issues: string[] }
+  | { status: "not-found" };
+
+export type PublicRouteResult =
+  | { type: "page"; snapshot: PageSnapshot }
+  | { type: "redirect"; location: string; status: 308 }
+  | { type: "not-found" };
+
+export interface LifecycleOptions {
+  idFactory?: () => string;
+  now?: () => Date;
+}
+
+function copy<T>(value: T): T {
+  return structuredClone(value);
+}
+
+function hourStart(date: Date): Date {
+  const result = new Date(date);
+  result.setUTCMinutes(0, 0, 0);
+  return result;
+}
+
+function collectMediaIds(value: unknown, result = new Set<string>()): Set<string> {
+  if (Array.isArray(value)) {
+    for (const item of value) collectMediaIds(item, result);
+    return result;
+  }
+  if (!value || typeof value !== "object") return result;
+
+  for (const [key, item] of Object.entries(value)) {
+    if (key === "mediaId" && typeof item === "string") result.add(item);
+    collectMediaIds(item, result);
+  }
+  return result;
+}
+
+function collectDataSourceIds(
+  value: unknown,
+  result = new Set<string>(),
+): Set<string> {
+  if (Array.isArray(value)) {
+    for (const item of value) collectDataSourceIds(item, result);
+    return result;
+  }
+  if (!value || typeof value !== "object") return result;
+
+  for (const [key, item] of Object.entries(value)) {
+    if (key === "dataSourceId" && typeof item === "string") result.add(item);
+    collectDataSourceIds(item, result);
+  }
+  return result;
+}
+
+export class ContentLifecycle {
+  private readonly characters = new Map<string, CharacterIdentity>();
+  private readonly pages = new Map<string, StoredPage>();
+  private readonly dataSources = new Map<string, StoredDataSource>();
+  private readonly revisions = new Map<string, ContentRevision>();
+  private readonly characterAliases: CharacterAlias[] = [];
+  private readonly pageAliases: PageAlias[] = [];
+  private readonly outbox: DomainOutboxEvent[] = [];
+  private nextOutboxId = 1;
+  private readonly idFactory: () => string;
+  private readonly clock: () => Date;
+
+  constructor(options: LifecycleOptions = {}) {
+    this.idFactory = options.idFactory ?? (() => crypto.randomUUID());
+    this.clock = options.now ?? (() => new Date());
+  }
+
+  addCharacter(
+    input: Omit<CharacterIdentity, "visible"> & { visible?: boolean },
+  ): CharacterIdentity {
+    const slug = slugSchema.parse(input.slug);
+    if ([...this.characters.values()].some((item) => item.slug === slug)) {
+      throw new Error(`Character slug already exists: ${slug}`);
+    }
+    const character: CharacterIdentity = {
+      ...copy(input),
+      slug,
+      visible: input.visible ?? false,
+    };
+    this.characters.set(character.id, character);
+    return copy(character);
+  }
+
+  setCharacterVisibility(id: string, visible: boolean): CharacterIdentity | null {
+    const character = this.characters.get(id);
+    if (!character) return null;
+    character.visible = visible;
+    this.enqueue("directory", id, "directory.updated", 1, this.clock());
+    return copy(character);
+  }
+
+  renameCharacter(id: string, nextSlug: string): CharacterIdentity | null {
+    const character = this.characters.get(id);
+    if (!character) return null;
+    const slug = slugSchema.parse(nextSlug);
+    if (
+      [...this.characters.values()].some(
+        (item) => item.id !== id && item.slug === slug,
+      )
+    ) {
+      throw new Error(`Character slug already exists: ${slug}`);
+    }
+    if (slug !== character.slug) {
+      this.characterAliases.push({ oldSlug: character.slug, characterId: id });
+      character.slug = slug;
+      this.enqueue("directory", id, "directory.updated", 1, this.clock());
+    }
+    return copy(character);
+  }
+
+  addPage(
+    input: Omit<PageIdentity, "visible" | "version"> & {
+      visible?: boolean;
+      version?: number;
+      blocks?: SerializedBlock[];
+    },
+  ): PageIdentity {
+    if (!this.characters.has(input.characterId)) {
+      throw new Error(`Character does not exist: ${input.characterId}`);
+    }
+    const slug = slugSchema.parse(input.slug);
+    if (
+      [...this.pages.values()].some(
+        (page) =>
+          page.characterId === input.characterId && page.slug === slug,
+      )
+    ) {
+      throw new Error(`Page slug already exists for this character: ${slug}`);
+    }
+    const blocks = copy(input.blocks ?? []);
+    const invalid = validatePageBlocks(blocks).filter(
+      (resolution) => resolution.kind === "invalid",
+    );
+    if (invalid.length > 0) throw new Error("Initial page blocks are invalid.");
+
+    const page: StoredPage = {
+      id: input.id,
+      characterId: input.characterId,
+      slug,
+      title: input.title,
+      navOrder: input.navOrder,
+      visible: input.visible ?? false,
+      publicNote: input.publicNote,
+      version: input.version ?? 1,
+      blocks,
+      dependencies: {},
+    };
+    this.pages.set(page.id, page);
+    return copy(this.pageIdentity(page));
+  }
+
+  addDataSource(input: DataSourceSnapshot): DataSourceSnapshot {
+    const snapshot = dataSourceSnapshotSchema.parse(copy(input));
+    evaluateDataSource(snapshot);
+    this.dataSources.set(snapshot.id, {
+      id: snapshot.id,
+      name: snapshot.name,
+      fields: snapshot.fields,
+      currentVersion: snapshot.version,
+      versions: new Map([[snapshot.version, snapshot]]),
+    });
+    return copy(snapshot);
+  }
+
+  savePage(input: SavePageInput): MutationResult<PageSnapshot> {
+    const page = this.pages.get(input.pageId);
+    if (!page) return { status: "not-found" };
+    if (page.version !== input.expectedVersion) {
+      return { status: "conflict", currentVersion: page.version };
+    }
+
+    const issues: string[] = [];
+    const slugResult = slugSchema.safeParse(input.slug);
+    if (!slugResult.success) {
+      issues.push(...slugResult.error.issues.map((issue) => issue.message));
+    }
+    if (!input.title.trim()) issues.push("Page title cannot be blank.");
+
+    const resolutions = validatePageBlocks(input.blocks);
+    for (const resolution of resolutions) {
+      if (resolution.kind === "invalid") {
+        issues.push(
+          ...resolution.issues.map(
+            (issue) => `${resolution.block.type}: ${issue.message}`,
+          ),
+        );
+      }
+    }
+
+    const dependencyIds = collectDataSourceIds(
+      input.blocks.map((block) => block.config),
+    );
+    for (const dependencyId of dependencyIds) {
+      if (!this.dataSources.has(dependencyId)) {
+        issues.push(`Referenced data source does not exist: ${dependencyId}`);
+      }
+    }
+
+    if (issues.length > 0 || !slugResult.success) {
+      return { status: "validation-error", issues };
+    }
+
+    const duplicateSlug = [...this.pages.values()].some(
+      (candidate) =>
+        candidate.id !== page.id &&
+        candidate.characterId === page.characterId &&
+        candidate.slug === slugResult.data,
+    );
+    if (duplicateSlug) {
+      return {
+        status: "validation-error",
+        issues: [`Page slug already exists: ${slugResult.data}`],
+      };
+    }
+
+    const character = this.characters.get(page.characterId)!;
+    if (slugResult.data !== page.slug) {
+      this.pageAliases.push({
+        oldCharacterSlug: character.slug,
+        oldPageSlug: page.slug,
+        pageId: page.id,
+      });
+    }
+
+    page.slug = slugResult.data;
+    page.title = input.title.trim();
+    page.visible = input.visible;
+    page.publicNote = input.publicNote?.trim() || null;
+    page.blocks = resolutions.map((resolution) =>
+      resolution.kind === "ready" ? resolution.block : resolution.block,
+    );
+    page.version += 1;
+    page.dependencies = Object.fromEntries(
+      [...dependencyIds].map((id) => [id, page.dependencies[id] ?? null]),
+    );
+
+    const now = input.now ?? this.clock();
+    this.upsertCheckpoint(page, input.authorId, now);
+    this.enqueue(`page:${page.id}`, page.id, "page.updated", page.version, now);
+    this.enqueue("directory", page.id, "directory.updated", page.version, now);
+    this.enqueue("admin", page.id, "admin.updated", page.version, now);
+
+    return { status: "accepted", value: this.snapshotFor(page) };
+  }
+
+  saveDataSource(
+    input: Omit<DataSourceSnapshot, "version"> & {
+      expectedVersion: number;
+      now?: Date;
+    },
+  ): MutationResult<DataSourceSnapshot> {
+    const source = this.dataSources.get(input.id);
+    if (!source) return { status: "not-found" };
+    if (source.currentVersion !== input.expectedVersion) {
+      return { status: "conflict", currentVersion: source.currentVersion };
+    }
+
+    const next: DataSourceSnapshot = {
+      id: input.id,
+      name: input.name,
+      version: source.currentVersion + 1,
+      fields: copy(input.fields),
+      rows: copy(input.rows),
+    };
+    const parsed = dataSourceSnapshotSchema.safeParse(next);
+    if (!parsed.success) {
+      return {
+        status: "validation-error",
+        issues: parsed.error.issues.map((issue) => issue.message),
+      };
+    }
+
+    // Formula failures are retained as typed cell errors and do not reject
+    // unrelated valid changes. Structural validation failures do reject.
+    evaluateDataSource(parsed.data);
+    source.currentVersion = next.version;
+    source.name = next.name;
+    source.fields = next.fields;
+    source.versions.set(next.version, copy(next));
+
+    const now = input.now ?? this.clock();
+    this.enqueue(
+      `data-source:${source.id}`,
+      source.id,
+      "data-source.updated",
+      next.version,
+      now,
+    );
+    for (const page of this.pages.values()) {
+      if (
+        Object.hasOwn(page.dependencies, source.id) &&
+        page.dependencies[source.id] === null
+      ) {
+        this.enqueue(`page:${page.id}`, page.id, "page.updated", page.version, now);
+      }
+    }
+
+    return { status: "accepted", value: copy(next) };
+  }
+
+  createNamedRevision(
+    pageId: string,
+    label: string,
+    authorId: string,
+    now = this.clock(),
+  ): ContentRevision | null {
+    const page = this.pages.get(pageId);
+    if (!page) return null;
+    const revision = this.captureRevision(
+      page,
+      "named",
+      label.trim() || "รุ่นที่บันทึก",
+      authorId,
+      now,
+      null,
+    );
+    this.revisions.set(revision.id, revision);
+    return copy(revision);
+  }
+
+  restoreRevision(
+    revisionId: string,
+    expectedVersion: number,
+    authorId: string,
+    now = this.clock(),
+  ): MutationResult<PageSnapshot> {
+    const revision = this.revisions.get(revisionId);
+    if (!revision) return { status: "not-found" };
+    const page = this.pages.get(revision.pageId);
+    if (!page) return { status: "not-found" };
+    if (page.version !== expectedVersion) {
+      return { status: "conflict", currentVersion: page.version };
+    }
+
+    const restored = revision.snapshot;
+    page.slug = restored.page.slug;
+    page.title = restored.page.title;
+    page.navOrder = restored.page.navOrder;
+    page.visible = restored.page.visible;
+    page.publicNote = restored.page.publicNote;
+    page.blocks = copy(restored.blocks);
+    page.dependencies = Object.fromEntries(
+      Object.keys(restored.dependencies).map((sourceId) => [
+        sourceId,
+        revision.dataSourceVersions[sourceId],
+      ]),
+    );
+    page.version += 1;
+
+    this.upsertCheckpoint(page, authorId, now, revision.id);
+    this.enqueue(`page:${page.id}`, page.id, "page.updated", page.version, now);
+    this.enqueue("directory", page.id, "directory.updated", page.version, now);
+    this.enqueue("admin", page.id, "admin.updated", page.version, now);
+    return { status: "accepted", value: this.snapshotFor(page) };
+  }
+
+  useLatestDataSource(
+    pageId: string,
+    dataSourceId: string,
+    expectedVersion: number,
+    authorId: string,
+    now = this.clock(),
+  ): MutationResult<PageSnapshot> {
+    const page = this.pages.get(pageId);
+    if (!page) return { status: "not-found" };
+    if (page.version !== expectedVersion) {
+      return { status: "conflict", currentVersion: page.version };
+    }
+    if (!Object.hasOwn(page.dependencies, dataSourceId)) {
+      return {
+        status: "validation-error",
+        issues: ["The page does not reference this data source."],
+      };
+    }
+
+    page.dependencies[dataSourceId] = null;
+    page.version += 1;
+    this.upsertCheckpoint(page, authorId, now);
+    this.enqueue(`page:${page.id}`, page.id, "page.updated", page.version, now);
+    this.enqueue("admin", page.id, "admin.updated", page.version, now);
+    return { status: "accepted", value: this.snapshotFor(page) };
+  }
+
+  expireCheckpoints(now = this.clock()): string[] {
+    const expired: string[] = [];
+    for (const [id, revision] of this.revisions) {
+      if (
+        revision.kind === "checkpoint" &&
+        revision.expiresAt &&
+        revision.expiresAt <= now
+      ) {
+        this.revisions.delete(id);
+        expired.push(id);
+      }
+    }
+    return expired;
+  }
+
+  getRevision(id: string): ContentRevision | null {
+    const revision = this.revisions.get(id);
+    return revision ? copy(revision) : null;
+  }
+
+  listRevisions(pageId: string): ContentRevision[] {
+    return [...this.revisions.values()]
+      .filter((revision) => revision.pageId === pageId)
+      .sort((left, right) => right.createdAt.getTime() - left.createdAt.getTime())
+      .map(copy);
+  }
+
+  getOutbox(): DomainOutboxEvent[] {
+    return this.outbox.map(copy);
+  }
+
+  markOutboxProcessed(id: number): void {
+    const event = this.outbox.find((item) => item.id === id);
+    if (event) event.status = "processed";
+  }
+
+  getDirectory(): PublicCharacterCard[] {
+    return [...this.characters.values()]
+      .filter((character) => character.visible)
+      .map((character) => {
+        const firstPage = this.visiblePagesFor(character.id)[0];
+        if (!firstPage) return null;
+        return {
+          id: character.id,
+          slug: character.slug,
+          nameTh: character.nameTh,
+          nameEn: character.nameEn,
+          portraitMediaId: character.portraitMediaId,
+          element: character.element,
+          role: character.role,
+          rarity: character.rarity,
+          firstPageSlug: firstPage.slug,
+        } satisfies PublicCharacterCard;
+      })
+      .filter((item): item is PublicCharacterCard => item !== null)
+      .sort((left, right) => {
+        const leftCharacter = this.characters.get(left.id)!;
+        const rightCharacter = this.characters.get(right.id)!;
+        return (
+          leftCharacter.sortOrder - rightCharacter.sortOrder ||
+          left.nameTh.localeCompare(right.nameTh, "th")
+        );
+      });
+  }
+
+  resolvePublicRoute(
+    characterSlug: string,
+    pageSlug?: string,
+  ): PublicRouteResult {
+    const currentCharacter = [...this.characters.values()].find(
+      (character) => character.slug === characterSlug,
+    );
+    const characterAlias = this.characterAliases.find(
+      (alias) => alias.oldSlug === characterSlug,
+    );
+    const character =
+      currentCharacter ??
+      (characterAlias
+        ? this.characters.get(characterAlias.characterId)
+        : undefined);
+
+    if (!character?.visible) return { type: "not-found" };
+
+    const visiblePages = this.visiblePagesFor(character.id);
+    if (visiblePages.length === 0) return { type: "not-found" };
+
+    if (!pageSlug) {
+      return {
+        type: "redirect",
+        location: `/${character.slug}/${visiblePages[0].slug}`,
+        status: 308,
+      };
+    }
+
+    const page = visiblePages.find((candidate) => candidate.slug === pageSlug);
+    if (page) {
+      if (!currentCharacter) {
+        return {
+          type: "redirect",
+          location: `/${character.slug}/${page.slug}`,
+          status: 308,
+        };
+      }
+      return { type: "page", snapshot: this.snapshotFor(page) };
+    }
+
+    const pageAlias = this.pageAliases.find(
+      (alias) =>
+        alias.oldCharacterSlug === characterSlug &&
+        alias.oldPageSlug === pageSlug,
+    );
+    const target = pageAlias ? this.pages.get(pageAlias.pageId) : undefined;
+    if (target?.visible && target.characterId === character.id) {
+      return {
+        type: "redirect",
+        location: `/${character.slug}/${target.slug}`,
+        status: 308,
+      };
+    }
+
+    return { type: "not-found" };
+  }
+
+  isMediaPublic(mediaId: string): boolean {
+    for (const page of this.pages.values()) {
+      const character = this.characters.get(page.characterId);
+      if (
+        character?.visible &&
+        page.visible &&
+        collectMediaIds(page.blocks.map((block) => block.config)).has(mediaId)
+      ) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  isMediaRetained(mediaId: string): boolean {
+    if (
+      [...this.pages.values()].some((page) =>
+        collectMediaIds(page.blocks.map((block) => block.config)).has(mediaId),
+      )
+    ) {
+      return true;
+    }
+    return [...this.revisions.values()].some((revision) =>
+      revision.mediaIds.includes(mediaId),
+    );
+  }
+
+  private pageIdentity(page: StoredPage): PageIdentity {
+    const { blocks: _blocks, dependencies: _dependencies, ...identity } = page;
+    return identity;
+  }
+
+  private visiblePagesFor(characterId: string): StoredPage[] {
+    return [...this.pages.values()]
+      .filter((page) => page.characterId === characterId && page.visible)
+      .sort(
+        (left, right) =>
+          left.navOrder - right.navOrder || left.title.localeCompare(right.title, "th"),
+      );
+  }
+
+  private versionVector(page: StoredPage): Record<string, number> {
+    return Object.fromEntries(
+      Object.entries(page.dependencies).map(([sourceId, pinnedVersion]) => {
+        const source = this.dataSources.get(sourceId);
+        return [sourceId, pinnedVersion ?? source?.currentVersion ?? 0];
+      }),
+    );
+  }
+
+  private snapshotFor(page: StoredPage): PageSnapshot {
+    const character = this.characters.get(page.characterId);
+    if (!character) throw new Error(`Character does not exist: ${page.characterId}`);
+    const vector = this.versionVector(page);
+    const sources = Object.fromEntries(
+      Object.entries(vector).flatMap(([sourceId, version]) => {
+        const source = this.dataSources.get(sourceId)?.versions.get(version);
+        return source ? [[sourceId, copy(source)] as const] : [];
+      }),
+    );
+
+    return {
+      character: copy(character),
+      page: copy(this.pageIdentity(page)),
+      pages: [...this.pages.values()]
+        .filter((candidate) => candidate.characterId === page.characterId)
+        .sort((left, right) => left.navOrder - right.navOrder)
+        .map((candidate) => copy(this.pageIdentity(candidate))),
+      blocks: copy(page.blocks),
+      dataSources: sources,
+      versionVector: vector,
+    };
+  }
+
+  private captureRevision(
+    page: StoredPage,
+    kind: ContentRevision["kind"],
+    label: string | null,
+    authorId: string,
+    now: Date,
+    sourceRevisionId: string | null,
+  ): ContentRevision {
+    const checkpointHour = kind === "checkpoint" ? hourStart(now) : null;
+    return {
+      id: this.idFactory(),
+      pageId: page.id,
+      pageVersion: page.version,
+      kind,
+      label,
+      authorId,
+      sourceRevisionId,
+      checkpointHour: checkpointHour?.toISOString() ?? null,
+      snapshot: {
+        page: copy(this.pageIdentity(page)),
+        blocks: copy(page.blocks),
+        dependencies: copy(page.dependencies),
+      },
+      dataSourceVersions: this.versionVector(page),
+      mediaIds: [
+        ...collectMediaIds(page.blocks.map((block) => block.config)),
+      ],
+      createdAt: new Date(now),
+      expiresAt:
+        kind === "checkpoint"
+          ? new Date(now.getTime() + checkpointRetentionMs)
+          : null,
+    };
+  }
+
+  private upsertCheckpoint(
+    page: StoredPage,
+    authorId: string,
+    now: Date,
+    sourceRevisionId: string | null = null,
+  ): void {
+    const next = this.captureRevision(
+      page,
+      "checkpoint",
+      null,
+      authorId,
+      now,
+      sourceRevisionId,
+    );
+    const existing = [...this.revisions.values()].find(
+      (revision) =>
+        revision.pageId === page.id &&
+        revision.kind === "checkpoint" &&
+        revision.checkpointHour === next.checkpointHour,
+    );
+    if (existing) this.revisions.delete(existing.id);
+    this.revisions.set(next.id, next);
+  }
+
+  private enqueue(
+    topic: string,
+    aggregateId: string,
+    eventType: DomainOutboxEvent["eventType"],
+    version: number,
+    now: Date,
+  ): void {
+    this.outbox.push({
+      id: this.nextOutboxId,
+      topic,
+      aggregateId,
+      eventType,
+      payload: { id: aggregateId, version },
+      status: "pending",
+      attempts: 0,
+      availableAt: new Date(now),
+      createdAt: new Date(now),
+    });
+    this.nextOutboxId += 1;
+  }
+}