feat(desktop): add Photon iMessage section to sidebar

Register Photon as a messaging platform in the Desktop sidebar:
- Add Photon brand icon (three-bar mark) to PlatformAvatar catalog
- Add photon to SOURCE_LABELS, SOURCE_ALIASES, and MESSAGING_SESSION_SOURCE_IDS

Closes #46761

apps/desktop/src/app/messaging/platform-icon.tsx

@@ -18,6 +18,22 @@ import { forwardRef } from 'react'
 import { Globe, Link as LinkIcon, MessageSquareText } from '@/lib/icons'
 import { cn } from '@/lib/utils'
 
+// ---------------------------------------------------------------------------
+// Photon brand icon — three diagonal rounded bars (the Photon logo mark).
+// Rendered at ~14 px inside the PlatformAvatar so the bars are kept thick
+// enough to stay legible. At small sizes the bars blend into a distinctive
+// silhouette; the wide triangular spacing preserves the logo's identity.
+// ---------------------------------------------------------------------------
+function PhotonIcon(props: React.SVGProps<SVGSVGElement>) {
+  return (
+    <svg fill="currentColor" viewBox="0 0 24 24" {...props}>
+      <rect height="10" rx="1.25" transform="rotate(15 14 7.5)" width="2.5" x="12.75" y="2.5" />
+      <rect height="10" rx="1.25" transform="rotate(15 8 13)" width="2.5" x="6.75" y="8" />
+      <rect height="10" rx="1.25" transform="rotate(15 16 18)" width="2.5" x="14.75" y="13" />
+    </svg>
+  )
+}
+
 // We render simpleicons.org brand glyphs for platforms whose owners publish a
 // usable mark (telegram, discord, matrix, ...). A few brands — Slack, Dingtalk,
 // Feishu, WeCom — have been removed from Simple Icons at the brand owner's
@@ -45,6 +61,7 @@ const PLATFORM_ICONS: Record<string, PlatformIconSpec> = {
   signal: { Icon: SiSignal, color: '#3A76F0', kind: 'brand' },
   whatsapp: { Icon: SiWhatsapp, color: '#25D366', kind: 'brand' },
   bluebubbles: { Icon: SiApple, color: '#0BD318', kind: 'brand' },
+  photon: { Icon: PhotonIcon, color: '#6366F1', kind: 'brand' },
   homeassistant: { Icon: SiHomeassistant, color: '#18BCF2', kind: 'brand' },
   email: { Icon: SiGmail, color: '#EA4335', kind: 'brand' },
   sms: { Icon: MessageSquareText, color: '#F43F5E', kind: 'generic' },

apps/desktop/src/lib/session-source.ts

@@ -12,6 +12,7 @@ const SOURCE_LABELS: Record<string, string> = {
   local: 'Local',
   matrix: 'Matrix',
   mattermost: 'Mattermost',
+  photon: 'Photon',
   qqbot: 'QQ',
   signal: 'Signal',
   slack: 'Slack',
@@ -26,6 +27,7 @@ const SOURCE_LABELS: Record<string, string> = {
 
 const SOURCE_ALIASES: Record<string, string[]> = {
   bluebubbles: ['apple messages', 'imessage'],
+  photon: ['imessage', 'messages'],
   cli: ['terminal'],
   desktop: ['app', 'gui'],
   local: ['machine'],
@@ -55,6 +57,7 @@ export const MESSAGING_SESSION_SOURCE_IDS = [
   'signal',
   'whatsapp',
   'bluebubbles',
+  'photon',
   'homeassistant',
   'email',
   'sms',