docs: improve doucmentation

improve doucmentation and fix small store changes

docs-site/docs/plugin-development/api/message-bus.md

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+---
+sidebar_position: 8
+---
+
+# Message Bus API
+
+The plugin message bus sends plugin-only P2P events. It can also include bounded latest-message snapshots for plugins that coordinate around recent chat state.
+
+## Required Capabilities
+
+| Method | Capability |
+| --- | --- |
+| `messageBus.publish(request)` | `events.p2p.publish`, plus `messages.read` if `includeLatestMessages` is true |
+| `messageBus.sendLatestMessages(request?)` | `events.p2p.publish` and `messages.read` |
+| `messageBus.subscribe(subscription)` | `events.p2p.subscribe`, plus `messages.read` if replaying latest messages |
+
+## Subscribe
+
+```js
+export function activate(context) {
+  context.subscriptions.push(context.api.messageBus.subscribe({
+    topic: 'poll:votes',
+    channelId: 'general',
+    replayLatest: true,
+    latestMessageLimit: 10,
+    handler: (event) => {
+      context.api.logger.info('Poll bus event', {
+        topic: event.topic,
+        choice: event.payload?.choice,
+        messageCount: event.messages?.length ?? 0
+      });
+    }
+  }));
+}
+```
+
+## Publish
+
+```js
+export function activate(context) {
+  const envelope = context.api.messageBus.publish({
+    topic: 'poll:votes',
+    channelId: 'general',
+    payload: {
+      pollId: 'raid-night-2026-04-29',
+      choice: 'healer',
+      voter: 'Alice'
+    },
+    includeLatestMessages: true,
+    includeSelf: true,
+    latestMessageLimit: 10,
+    sinceTimestamp: 1777470000000
+  });
+
+  context.api.logger.info('Published poll event', { eventId: envelope.eventId });
+}
+```
+
+Example envelope:
+
+```json
+{
+  "eventId": "plugin-bus-1777473600000-1",
+  "pluginId": "example.polls",
+  "roomId": "room-7ebdde75",
+  "channelId": "general",
+  "topic": "poll:votes",
+  "sentAt": 1777473600000,
+  "payload": {
+    "pollId": "raid-night-2026-04-29",
+    "choice": "healer",
+    "voter": "Alice"
+  },
+  "messages": [
+    { "id": "msg-1", "content": "Raid tonight?", "channelId": "general" }
+  ]
+}
+```
+
+## Send Latest Messages
+
+```js
+export function activate(context) {
+  context.api.messageBus.sendLatestMessages({
+    topic: 'chat:snapshot',
+    channelId: 'support',
+    limit: 25,
+    includeDeleted: false,
+    sinceTimestamp: 1777460000000,
+    targetPeerId: 'peer-muse-laptop'
+  });
+}
+```
+
+Use the message bus for plugin coordination. Do not use it for normal user chat messages; use `messages.send()` for that.