move labeler cache to mmkv, make moderation config sync

The per-account labeler cache was the only async dependency in
configureModerationForAccount. MMKV-backed sync reads let session
bundle prep apply labelers in the same tick. No AsyncStorage
backfill: the cache is rewritten on every preferences fetch.

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

src/state/queries/preferences/index.ts

@@ -39,8 +39,7 @@ import {
 } from '#/state/queries/preferences/types'
 import {createQueryKey} from '#/state/queries/util'
 import {useAppviewClient, usePdsClient} from '#/state/session'
-import {saveLabelers} from '#/state/session/agent-config'
-import {applyLabelersToClient} from '#/state/session/moderation'
+import {applyLabelersToClient, saveLabelers} from '#/state/session/moderation'
 import {useAgeAssurance} from '#/ageAssurance'
 import {makeAgeRestrictedModerationPrefs} from '#/ageAssurance/util'
 import {useAnalytics} from '#/analytics'
@@ -76,7 +75,7 @@ export function usePreferencesQuery() {
         const labelerDids = res.moderationPrefs.labelers.map(l => l.did)
 
         // save to local storage to ensure there are labels on initial requests
-        void saveLabelers(client.did, labelerDids)
+        saveLabelers(client.did, labelerDids)
 
         /*
          * Sync the subscribed labelers to the live appview client, mirroring the

src/state/session/agent-config.ts

@@ -1,12 +0,0 @@
-import AsyncStorage from '@react-native-async-storage/async-storage'
-
-const PREFIX = 'agent-labelers'
-
-export async function saveLabelers(did: string, value: string[]) {
-  await AsyncStorage.setItem(`${PREFIX}:${did}`, JSON.stringify(value))
-}
-
-export async function readLabelers(did: string): Promise<string[] | undefined> {
-  const rawData = await AsyncStorage.getItem(`${PREFIX}:${did}`)
-  return rawData ? JSON.parse(rawData) : undefined
-}

src/storage/schema.ts

@@ -108,4 +108,15 @@ export type Account = {
    * account after a switch, until that account's preferences loaded.
    */
   isBetaUser?: boolean
+
+  /**
+   * The account's subscribed labeler DIDs, cached from preferences so the
+   * `atproto-accept-labelers` header can be configured synchronously at
+   * session start, before preferences load. Eventually consistent: rewritten
+   * on every preferences fetch (see `saveLabelers` in
+   * `#/state/session/moderation`). Until the first fetch lands there is
+   * simply no cache entry and initial requests go out without per-account
+   * labeler headers.
+   */
+  labelers?: string[]
 }