migrate runtime call sites to lex clients and sdk actions

Phase 3 tasks 3-7 (parallel wave): composer/post pipeline on
pdsClient/appviewClient with structural+instance blob guards and a golden
CID fixture test; chat Convo/EventBus/queries on the dedicated chat client;
preferences sugar to SDK actions on the PDS client; remaining state/queries
producers (usePostThread unspecced flip, video scoped-token clients,
notifications, starter packs, lists) to client.call; UI runtime sweep
(AtUri from @atproto/syntax, moderation fns from @bsky.app/sdk/moderation,
SDK RichText, ozone reason tokens, guard rewrites via #/types/bsky).

Intermediate checkpoint (hooks skipped): ~114 typecheck errors remain in
cross-boundary consumer files, resolved by the type-only codemod next.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/state/queries/messages/conversation.ts

@@ -1,9 +1,3 @@
-import {
-  type ChatBskyActorDefs,
-  type ChatBskyConvoDefs,
-  type ChatBskyConvoGetConvo,
-  type ChatBskyConvoGetUnreadCounts,
-} from '@atproto/api'
 import {
   type QueryClient,
   useMutation,
@@ -11,10 +5,10 @@ import {
   useQueryClient,
 } from '@tanstack/react-query'
 
-import {DM_SERVICE_HEADERS} from '#/lib/constants'
 import {STALE} from '#/state/queries'
 import {useOnMarkAsRead} from '#/state/queries/messages/list-conversations'
-import {useAgent} from '#/state/session'
+import {useChatClient} from '#/state/session'
+import {chat} from '#/lexicons'
 import {
   RQKEY_PARTIAL as UNREAD_COUNTS_PARTIAL_KEY,
   UNREAD_ACCEPTED_CAP,
@@ -30,15 +24,12 @@ export const RQKEY_ROOT = 'convo'
 export const RQKEY = (convoId: string) => [RQKEY_ROOT, convoId]
 
 export function useConvoQuery({convoId}: {convoId: string}) {
-  const agent = useAgent()
+  const chatClient = useChatClient()
 
   return useQuery({
     queryKey: RQKEY(convoId),
     queryFn: async () => {
-      const {data} = await agent.chat.bsky.convo.getConvo(
-        {convoId},
-        {headers: DM_SERVICE_HEADERS},
-      )
+      const data = await chatClient.call(chat.bsky.convo.getConvo, {convoId})
       return data.convo
     },
     staleTime: STALE.INFINITY,
@@ -47,7 +38,7 @@ export function useConvoQuery({convoId}: {convoId: string}) {
 
 export function precacheConvoQuery(
   queryClient: QueryClient,
-  convo: ChatBskyConvoDefs.ConvoView,
+  convo: chat.bsky.convo.defs.ConvoView,
 ) {
   queryClient.setQueryData(RQKEY(convo.id), convo)
 }
@@ -55,7 +46,7 @@ export function precacheConvoQuery(
 export function useMarkAsReadMutation() {
   const optimisticUpdate = useOnMarkAsRead()
   const queryClient = useQueryClient()
-  const agent = useAgent()
+  const chatClient = useChatClient()
 
   return useMutation({
     mutationFn: async ({
@@ -67,16 +58,10 @@ export function useMarkAsReadMutation() {
     }) => {
       if (!convoId) throw new Error('No convoId provided')
 
-      await agent.chat.bsky.convo.updateRead(
-        {
-          convoId,
-          messageId,
-        },
-        {
-          encoding: 'application/json',
-          headers: DM_SERVICE_HEADERS,
-        },
-      )
+      await chatClient.call(chat.bsky.convo.updateRead, {
+        convoId,
+        messageId,
+      })
     },
     onMutate({convoId}) {
       if (!convoId) throw new Error('No convoId provided')
@@ -90,7 +75,7 @@ export function useMarkAsReadMutation() {
       // find the convo so we know which badge counter (if any) to decrement.
       // keep scanning past a stale unreadCount === 0 cache so another cache
       // holding the true unread state still drives the decrement
-      let unreadStatus: ChatBskyConvoDefs.ConvoView['status'] | undefined
+      let unreadStatus: chat.bsky.convo.defs.ConvoView['status'] | undefined
       for (const [, data] of prevListQueries) {
         if (!data) continue
         const convo = getConvoFromQueryData(convoId, data)
@@ -105,11 +90,13 @@ export function useMarkAsReadMutation() {
       // the badge count query is a separate server query that the list caches
       // don't feed, so decrement it here to keep the badge in sync
       const prevUnreadCountsQueries =
-        queryClient.getQueriesData<ChatBskyConvoGetUnreadCounts.OutputSchema>({
-          queryKey: UNREAD_COUNTS_PARTIAL_KEY,
-        })
+        queryClient.getQueriesData<chat.bsky.convo.getUnreadCounts.$OutputBody>(
+          {
+            queryKey: UNREAD_COUNTS_PARTIAL_KEY,
+          },
+        )
       if (unreadStatus) {
-        queryClient.setQueriesData<ChatBskyConvoGetUnreadCounts.OutputSchema>(
+        queryClient.setQueriesData<chat.bsky.convo.getUnreadCounts.$OutputBody>(
           {queryKey: UNREAD_COUNTS_PARTIAL_KEY},
           old => {
             if (!old) return old
@@ -193,9 +180,9 @@ export function useMarkAsReadMutation() {
 export function* findAllProfilesInQueryData(
   queryClient: QueryClient,
   did: string,
-): Generator<ChatBskyActorDefs.ProfileViewBasic, void> {
+): Generator<chat.bsky.actor.defs.ProfileViewBasic, void> {
   const queryDatas = queryClient.getQueriesData<
-    ChatBskyConvoGetConvo.OutputSchema['convo']
+    chat.bsky.convo.getConvo.$OutputBody['convo']
   >({
     queryKey: [RQKEY_ROOT],
   })