rework session layer on PasswordSession + three-client pattern

- PasswordSession (@atproto/lex-password-session) is now the single auth
  core; SessionAgent bridges it to the base Agent from @atproto/api so
  the ~148 useAgent() consumer files keep working unchanged
- SessionBundle carries {session, agent, accountClient, appviewClient};
  useLexClient() now returns the authed appview client, new
  useAppviewClient()/usePdsClient() hooks
- reducer: OpaqueSessionBundle, new replaced-current-bundle action for
  network-free cross-tab same-did sync (PasswordSession is immutable, so
  the bundle is rebuilt instead of mutated in place)
- moderation: AtpAgent.configure -> Client.configure + Agent.configure,
  per-account labelers on both the bridge and the appview client
- push-token unregistration uses temporary PasswordSessions
- hard-tail migrations: SignupQueued refresh via resumeSession shim,
  useBeginAgeAssurance scoped-token raw Client, useAccountEmailState
  reads currentAccount
- PDS routing preserved on the no-network resume fast path by
  synthesizing a minimal didDoc from the persisted pdsUrl

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

src/state/queries/messages/actor-declaration.ts

@@ -1,4 +1,3 @@
-import type AtpAgent from '@atproto/api'
 import {
   type AppBskyActorDefs,
   type ChatBskyActorDeclaration,
@@ -6,6 +5,7 @@ import {
 import {useMutation, useQueryClient} from '@tanstack/react-query'
 
 import {logger} from '#/logger'
+import {type SessionAgent} from '#/state/session'
 import {useAgent, useSession} from '#/state/session'
 import {resolveAllowGroupInvites} from '#/components/dms/util'
 import {RQKEY as PROFILE_RKEY} from '../profile'
@@ -120,7 +120,7 @@ export async function fetchActorDeclarationRecord({
   agent,
   did,
 }: {
-  agent: AtpAgent
+  agent: SessionAgent
   did?: string
 }) {
   if (!did) return