feat(v0.8.670): slash registry CSV and invoke audit mesh parity

Implement Phase 695 signed slash command registry CSV and slash invoke
audit export across delivery-receipts, platform gossip (RPC 108/109),
slash-csv-ui modal, agentctl journeys, and test:ci-phase695 regression.

Also backfill relay/worker CSV styles missing from pearcord.css and bump
phase687 boot gate to 0.8.670 for RELEASE_CI continuity.

headless.js

@@ -3608,6 +3608,45 @@ class HeadlessSession {
     }
   }
 
+  async runSlashRegistryCsvJourney () {
+    if (!this.platform) throw new Error('headless not started')
+    await this.registerUser({ username: 'sr695', displayName: 'Slash CSV 695' })
+    await this.createGuild({ name: 'Slash CSV 695', publicListing: false })
+    await this.wait({ mode: 'guild' }, 45000)
+    await this.platform.registerSlashCommands([
+      { name: 'phase695_ping', description: 'Phase 695 slash CSV journey' }
+    ])
+    const pushed = await this.platform.pushSlashRegistryCsvToMesh()
+    const v = await this.refreshView()
+    if (!pushed?.signature && !v.slashRegistryCsvMeta?.signature) {
+      throw new Error('expected signed slash registry CSV after mesh push')
+    }
+    return {
+      guildSlashRegistryCount: (v.slashRegistryCsvRows || []).length,
+      hasMeta: v.slashRegistryCsvMeta != null
+    }
+  }
+
+  async runSlashInvokeAuditExportJourney () {
+    if (!this.platform) throw new Error('headless not started')
+    await this.registerUser({ username: 'si695', displayName: 'Slash Invoke 695' })
+    await this.createGuild({ name: 'Slash Invoke 695', publicListing: false })
+    await this.wait({ mode: 'guild' }, 45000)
+    await this.platform.registerSlashCommands([
+      { name: 'phase695_audit', description: 'Phase 695 invoke audit export' }
+    ])
+    const pushed = await this.platform.pushSlashInvokeAuditExportToMesh()
+    const v = await this.refreshView()
+    if (!pushed?.signature) {
+      throw new Error('expected signed slash invoke audit CSV export')
+    }
+    return {
+      guildSlashRegistryCount: (v.slashInvokeAuditExportCsvRows || []).length,
+      hasInvokeExport:
+        v.lastSlashInvokeAuditExport != null || (v.slashInvokeAuditExportCsvRows || []).length > 0
+    }
+  }
+
   async runForumPostSearchJourney () {
     if (!this.platform) throw new Error('headless not started')
     await this.registerUser({ username: 'fm672', displayName: 'Forum 672' })