[SDK] Delete the bridge agent and rework the session bundle onto lex clients (#11385)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

src/lib/constants.ts

@@ -2,7 +2,6 @@ import {type Insets, Platform} from 'react-native'
 import {type AppBskyActorDefs, BSKY_LABELER_DID} from '@atproto/api'
 import {type Service} from '@atproto/lex'
 
-import {type ProxyHeaderValue} from '#/state/session/agent'
 import {BLUESKY_PROXY_DID, CHAT_PROXY_DID, IS_DEV} from '#/env'
 
 export const LOCAL_DEV_SERVICE =
@@ -241,7 +240,7 @@ export const DEV_ENV_APPVIEW_DID = `did:plc:dw4kbjf5mn7nhenabiqpkyh3` // always
 export const BLUESKY_PROXY_HEADER = {
   value: `${BLUESKY_PROXY_DID}#bsky_appview`,
   get() {
-    return this.value as ProxyHeaderValue
+    return this.value as Service
   },
   set(value: string) {
     this.value = value
@@ -257,9 +256,6 @@ export const BLUESKY_PROXY_HEADER = {
  * The DID comes from the env-configurable `CHAT_PROXY_DID` (via
  * `EXPO_PUBLIC_CHAT_PROXY_DID`) rather than a hard-coded constant, so the
  * target can be retargeted per environment.
- *
- * This is the client-level equivalent of {@link DM_SERVICE_HEADERS}, which
- * carries the same value as a per-call header.
  */
 export const CHAT_PROXY_SERVICE: Service = `${CHAT_PROXY_DID}#bsky_chat`
 
@@ -275,10 +271,6 @@ export const CHAT_PROXY_SERVICE: Service = `${CHAT_PROXY_DID}#bsky_chat`
  */
 export const MOD_PROXY_SERVICE: Service = `${BSKY_LABELER_DID}#atproto_labeler`
 
-export const DM_SERVICE_HEADERS = {
-  'atproto-proxy': `${CHAT_PROXY_DID}#bsky_chat`,
-}
-
 /**
  * The notification service's proxy target, in the `did#service_id` form a lex
  * client's per-call `service` option takes. Passing it emits `atproto-proxy: