feat: Security

toju-app/src/app/infrastructure/persistence/browser-database-schema.ts

@@ -1,5 +1,5 @@
 /** IndexedDB schema version - bump when adding/changing object stores. */
-export const BROWSER_DATABASE_VERSION = 3;
+export const BROWSER_DATABASE_VERSION = 4;
 
 const STORE_MESSAGES = 'messages';
 const STORE_USERS = 'users';
@@ -9,6 +9,7 @@ const STORE_BANS = 'bans';
 const STORE_META = 'meta';
 const STORE_ATTACHMENTS = 'attachments';
 const STORE_CUSTOM_EMOJIS = 'customEmojis';
+const STORE_MESSAGE_REVISIONS = 'messageRevisions';
 
 export function ensureObjectStoreDuringUpgrade(
   database: IDBDatabase,
@@ -64,4 +65,8 @@ export function applyBrowserDatabaseSchema(
 
   ensureStoreIndex(customEmojisStore, 'updatedAt', 'updatedAt');
   ensureStoreIndex(customEmojisStore, 'creatorUserId', 'creatorUserId');
+
+  const revisionsStore = ensureObjectStoreDuringUpgrade(database, upgradeTransaction, STORE_MESSAGE_REVISIONS, { keyPath: 'id' });
+
+  ensureStoreIndex(revisionsStore, 'messageId', 'messageId');
 }

toju-app/src/app/infrastructure/persistence/browser-database.service.ts

@@ -6,7 +6,8 @@ import {
   User,
   Room,
   Reaction,
-  BanEntry
+  BanEntry,
+  type MessageRevision
 } from '../../shared-kernel';
 import type { ChatAttachmentMeta, CustomEmoji } from '../../shared-kernel';
 import { getStoredCurrentUserId } from '../../core/storage/current-user-storage';
@@ -25,6 +26,7 @@ const STORE_BANS = 'bans';
 const STORE_META = 'meta';
 const STORE_ATTACHMENTS = 'attachments';
 const STORE_CUSTOM_EMOJIS = 'customEmojis';
+const STORE_MESSAGE_REVISIONS = 'messageRevisions';
 /** All object store names, used when clearing the entire database. */
 const ALL_STORE_NAMES: string[] = [
   STORE_MESSAGES,
@@ -34,6 +36,7 @@ const ALL_STORE_NAMES: string[] = [
   STORE_BANS,
   STORE_ATTACHMENTS,
   STORE_CUSTOM_EMOJIS,
+  STORE_MESSAGE_REVISIONS,
   STORE_META
 ];
 
@@ -67,6 +70,13 @@ export class BrowserDatabaseService {
     await this.put(STORE_MESSAGES, message);
   }
 
+  async saveMessageRevision(revision: MessageRevision): Promise<void> {
+    await this.put(STORE_MESSAGE_REVISIONS, {
+      ...revision,
+      id: `${revision.messageId}:${revision.revision}`
+    });
+  }
+
   /**
     * Retrieve the latest messages for a room, sorted oldest-first for display.
    * @param roomId - Target room.

toju-app/src/app/infrastructure/persistence/capacitor-database.service.ts

@@ -7,7 +7,7 @@ import {
   type Room,
   type User
 } from '../../shared-kernel';
-import type { ChatAttachmentMeta, CustomEmoji } from '../../shared-kernel';
+import type { ChatAttachmentMeta, CustomEmoji, MessageRevision } from '../../shared-kernel';
 import { getStoredCurrentUserId } from '../../core/storage/current-user-storage';
 import {
   attachmentToValues,
@@ -42,6 +42,15 @@ export class CapacitorDatabaseService {
     await this.connection.initialize();
   }
 
+  async saveMessageRevision(revision: MessageRevision): Promise<void> {
+    const store = await this.connection.getStore();
+
+    await store.run(
+      'INSERT OR REPLACE INTO meta (key, value) VALUES (?, ?)',
+      [`message-revision:${revision.messageId}:${revision.revision}`, JSON.stringify(revision)]
+    );
+  }
+
   async saveMessage(message: Message): Promise<void> {
     const store = await this.connection.getStore();
     const row = messageToRow(message);
@@ -49,8 +58,9 @@ export class CapacitorDatabaseService {
     await store.run(
       `INSERT OR REPLACE INTO messages (
         id, roomId, ownerUserId, channelId, senderId, senderName, content,
-        timestamp, editedAt, isDeleted, replyToId, linkMetadata, kind, systemEvent
-      ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+        timestamp, editedAt, isDeleted, replyToId, linkMetadata, kind, systemEvent,
+        revision, headHash
+      ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
       [
         row.id,
         row.roomId,
@@ -65,7 +75,9 @@ export class CapacitorDatabaseService {
         row.replyToId ?? null,
         row.linkMetadata ?? null,
         row.kind ?? null,
-        row.systemEvent ?? null
+        row.systemEvent ?? null,
+        row.revision ?? 0,
+        row.headHash ?? null
       ]
     );
   }

toju-app/src/app/infrastructure/persistence/database.service.ts

@@ -9,7 +9,8 @@ import {
   User,
   Room,
   Reaction,
-  BanEntry
+  BanEntry,
+  type MessageRevision
 } from '../../shared-kernel';
 import type { ChatAttachmentMeta, CustomEmoji } from '../../shared-kernel';
 import { PlatformService } from '../../core/platform';
@@ -99,6 +100,11 @@ export class DatabaseService {
   /** Persist a single chat message. */
   saveMessage(message: Message) { return this.withReady(() => this.backend.saveMessage(message)); }
 
+  /** Persist an append-only message revision audit entry. */
+  saveMessageRevision(revision: MessageRevision) {
+    return this.withReady(() => this.backend.saveMessageRevision(revision));
+  }
+
   /** Retrieve the latest messages for a room or channel with optional pagination.
    *
    * When `beforeTimestamp` is provided, only messages strictly older than that

toju-app/src/app/infrastructure/persistence/electron-database.service.ts

@@ -4,7 +4,8 @@ import {
   User,
   Room,
   Reaction,
-  BanEntry
+  BanEntry,
+  type MessageRevision
 } from '../../shared-kernel';
 import type { CustomEmoji } from '../../shared-kernel';
 import type { ElectronApi } from '../../core/platform/electron/electron-api.models';
@@ -38,6 +39,16 @@ export class ElectronDatabaseService {
     return this.api.command({ type: 'save-message', payload: { message } });
   }
 
+  saveMessageRevision(revision: MessageRevision): Promise<void> {
+    return this.api.command({
+      type: 'save-meta',
+      payload: {
+        key: `message-revision:${revision.messageId}:${revision.revision}`,
+        value: JSON.stringify(revision)
+      }
+    });
+  }
+
   /**
     * Retrieve the latest messages for a room, sorted oldest-first for display.
    *