feat(platform): attachment and embed span metadata (Phase 502)

Add filenameLen on attachment.stage, attachmentId/isImage on attachment.read,
embed.gossip span, and gossipSent on embed.resolve.

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

README.md

@@ -61,6 +61,8 @@ Expose a single `EventEmitter` API the UI drives over IPC (`apps/pearcord/index.
 
 **v0.8.464 (Phase 501):** `reaction.toggle` `added`/`hadMeBefore`/`gossipSent`; `reaction.gossip` span on mesh fanout. UI `syncReactionPanelsDuringGuildLoading`. Bundle: `npm run test:phase501-reactions`. See [REACTIONS.md](../../docs/REACTIONS.md).
 
+**v0.8.465 (Phase 502):** `attachment.stage` `filenameLen`; `attachment.read` `attachmentId`/`isImage`; `embed.gossip` span; `embed.resolve` `gossipSent`. UI split attachment guild-loading compositor. Bundle: `npm run test:phase502-attachments`. See [ATTACHMENTS.md](../../docs/ATTACHMENTS.md), [EMBEDS.md](../../docs/EMBEDS.md).
+
 **v0.8.446 (Phase 483):** `guild.search` `includeMesh`/`queryLen`; `pin.list` `pinCount`. UI search compositor split + hints. Bundle: `npm run test:phase483-search`. See [SEARCH.md](../../docs/SEARCH.md).
 
 **v0.8.445 (Phase 482):** `message.send` `hasAttachment`/`hasSticker`; `message.edit` `contentChanged`; `message.delete` `wasOwn`. UI messaging compositor + hints. Bundle: `npm run test:phase482-messaging`. See [MESSAGING.md](../../docs/MESSAGING.md).

index.js

@@ -5090,6 +5090,7 @@ class PearcordPlatform extends EventEmitter {
         channelId,
         mimeType: rowMime,
         byteLength,
+        filenameLen: String(filename || '').length,
         isImage: String(rowMime || '').startsWith('image/')
       })
       return row
@@ -8082,13 +8083,28 @@ class PearcordPlatform extends EventEmitter {
     })
     try {
       const row = await this.embeds.resolveForContent(plain)
+      let gossipSent = false
       if (row && this.guild) {
+        const gossipSpan = this.log.time('embed.gossip', {
+          messageId: msg.id,
+          guildId,
+          channelId,
+          urlHost: (() => {
+            try {
+              return new URL(url).host
+            } catch (_) {
+              return null
+            }
+          })()
+        })
         this.guild.gossipLinkEmbed({
           ...row,
           messageId: msg.id,
           channelId: msg.channelId,
           guildId: msg.guildId
         })
+        gossipSpan.end({ resolved: true, guildId, channelId })
+        gossipSent = true
       }
       let urlHost = null
       try {
@@ -8101,7 +8117,8 @@ class PearcordPlatform extends EventEmitter {
         urlHost,
         urlLen: url.length,
         hasTitle: !!(row?.title),
-        hasImage: !!(row?.image || row?.thumbnail)
+        hasImage: !!(row?.image || row?.thumbnail),
+        gossipSent
       })
     } catch (err) {
       this.log.error('embed.resolve error', {