[Chat] Sync convo agent with shadow cache (#10827)

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Co-authored-by: DS Boyce <260543580+ds-boyce@users.noreply.github.com>
Co-authored-by: Samuel Newman <mozzius@protonmail.com>

src/state/cache/profile-shadow.ts

@@ -53,6 +53,21 @@ const shadows: WeakMap<
 > = new WeakMap()
 const emitter = new EventEmitter()
 
+type ShadowUpdateEventPayload = {did: string; shadow: Partial<ProfileShadow>}
+
+/**
+ * Subscribe to all profile shadow updates, regardless of did. Useful for
+ * non-React consumers like the Convo agent. Returns an unlisten function.
+ */
+export function listenProfileShadowUpdate(
+  listener: (payload: ShadowUpdateEventPayload) => void,
+): () => void {
+  emitter.addListener('shadow-update', listener)
+  return () => {
+    emitter.removeListener('shadow-update', listener)
+  }
+}
+
 export function useProfileShadow<
   TProfileView extends bsky.profile.AnyProfileView,
 >(profile: TProfileView): Shadow<TProfileView> {
@@ -206,10 +221,47 @@ export function updateProfileShadow(
   }
   batchedUpdates(() => {
     emitter.emit(did, value)
+    emitter.emit('shadow-update', {
+      did,
+      shadow: value,
+    } satisfies ShadowUpdateEventPayload)
   })
 }
 
-function mergeShadow<TProfileView extends bsky.profile.AnyProfileView>(
+/**
+ * Returns true if merging `shadow` into `profile` would change nothing, i.e.
+ * `mergeShadow` would be a no-op. Object-valued fields are compared by
+ * reference, so this can return false negatives - callers may do redundant
+ * merges, but never skip a real change.
+ */
+export function isProfileShadowApplied<
+  TProfileView extends bsky.profile.AnyProfileView,
+>(profile: TProfileView, shadow: Partial<ProfileShadow>): boolean {
+  if ('followingUri' in shadow) {
+    if (profile.viewer?.following !== shadow.followingUri) return false
+  }
+  if ('muted' in shadow) {
+    if (profile.viewer?.muted !== shadow.muted) return false
+  }
+  if ('blockingUri' in shadow) {
+    if (profile.viewer?.blocking !== shadow.blockingUri) return false
+  }
+  if ('activitySubscription' in shadow) {
+    if (profile.viewer?.activitySubscription !== shadow.activitySubscription) {
+      return false
+    }
+  }
+  if ('verification' in shadow) {
+    if (profile.verification !== shadow.verification) return false
+  }
+  if ('status' in shadow) {
+    const current = 'status' in profile ? profile.status : undefined
+    if (current !== shadow.status) return false
+  }
+  return true
+}
+
+export function mergeShadow<TProfileView extends bsky.profile.AnyProfileView>(
   profile: TProfileView,
   shadow: Partial<ProfileShadow>,
 ): Shadow<TProfileView> {