feat(platform): message span guildCount for Phase 584 (v0.8.547)

Extend message.send, message.edit, and message.delete span ends with
guildCount for messaging hub correlation.

Co-authored-by: Cursor <[email protected]>

README.md

@@ -229,6 +229,8 @@ Expose a single `EventEmitter` API the UI drives over IPC (`apps/pearcord/index.
 
 **v0.8.521 (Phase 558):** Voice spans extend — `voice.join`/`voice.leave`/`voice.mute` `activeChannelId`. UI `#voice-panel-live`, `syncVoiceOccupancyLivePanelDuringGuildLoading`. Bundle: `npm run test:phase558-voice`. See [VOICE.md](../../docs/VOICE.md).
 
+**v0.8.547 (Phase 584):** Message spans extend — `message.send`/`message.edit`/`message.delete` end adds `guildCount`. UI `#messaging-hub-panel-live`, `syncMessagingHubLivePanelDuringGuildLoading`; tightened **message-errors** bleed exclusions. Bundle: `npm run test:phase584-messaging`. See [MESSAGING.md](../../docs/MESSAGING.md).
+
 **v0.8.546 (Phase 583):** Attachment spans extend — `attachment.stage`/`attachment.read`/`attachment.unlink` end adds `guildCount`. UI `#attachment-hub-panel-live`, `syncAttachmentHubLivePanelDuringGuildLoading`; tightened **attachment-errors** bleed exclusions. Bundle: `npm run test:phase583-attachments`. See [ATTACHMENTS.md](../../docs/ATTACHMENTS.md).
 
 **v0.8.545 (Phase 582):** Embed spans extend — `embed.resolve`/`embed.gossip`/`embed.clear` end adds `guildCount`. UI `#embed-hub-panel-live`, `syncEmbedHubLivePanelDuringGuildLoading`; tightened **embed-errors** bleed exclusions. Bundle: `npm run test:phase582-embeds`. See [EMBEDS.md](../../docs/EMBEDS.md).

index.js

@@ -12055,6 +12055,7 @@ class PearcordPlatform extends EventEmitter {
         messageId: msg?.id,
         guildId,
         channelId,
+        guildCount: (this.guilds || []).length,
         contentLength: body.length,
         channelMessageCount: channelRows.length,
         remainingCharCapacity: Math.max(0, 2000 - body.length),
@@ -12228,6 +12229,7 @@ class PearcordPlatform extends EventEmitter {
         messageId: msg?.id,
         guildId,
         channelId,
+        guildCount: (this.guilds || []).length,
         contentLength: nextLength,
         priorLength,
         deltaLength: nextLength - priorLength,
@@ -13192,6 +13194,7 @@ class PearcordPlatform extends EventEmitter {
         messageId,
         guildId,
         channelId,
+        guildCount: (this.guilds || []).length,
         contentLength,
         hadAttachments,
         unlinkedAttachmentCount,