finish phase 3: type-only codemod and zero non-bridge @atproto/api imports

Task 8: codemod repointed 150 namespace-type files to #/lexicons
(AppBskyFeedDefs.PostView -> app.bsky.feed.defs.PostView, .Record -> .Main)
plus ~105 hand-fixed consumers (composer/video state, DebugMod, Profile,
onboarding, dialogs). DM_SERVICE_HEADERS deleted; last chat call sites on
the chat client. RichText.tsx flipped to SDK-only. Remaining @atproto/api
importers: the three session bridge files, the deliberate dual-world
matcher in lib/xrpc-error.ts, and test fixtures. toLex boundary casts are
TODO(phase4)-tagged for bridge removal.

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

src/components/dms/LeaveConvoPrompt.tsx

@@ -1,9 +1,9 @@
-import {ChatBskyConvoLeaveConvo} from '@atproto/api'
 import {useLingui} from '@lingui/react/macro'
 import {StackActions, useNavigation} from '@react-navigation/native'
 
 import {type NavigationProp} from '#/lib/routes/types'
 import {isNetworkError} from '#/lib/strings/errors'
+import {getErrorName} from '#/lib/xrpc-error'
 import {useLeaveConvo} from '#/state/queries/messages/leave-conversation'
 import {type DialogOuterProps} from '#/components/Dialog'
 import * as Prompt from '#/components/Prompt'
@@ -36,11 +36,9 @@ export function LeaveConvoPrompt({
       let errorMessage = l`Could not leave chat`
       if (isNetworkError(error)) {
         errorMessage = l`A network error occurred. Please check your internet connection.`
-      } else if (error instanceof ChatBskyConvoLeaveConvo.InvalidConvoError) {
+      } else if (getErrorName(error) === 'InvalidConvo') {
         errorMessage = l`Conversation not found.`
-      } else if (
-        error instanceof ChatBskyConvoLeaveConvo.OwnerCannotLeaveError
-      ) {
+      } else if (getErrorName(error) === 'OwnerCannotLeave') {
         errorMessage = l`Owner must lock the group before leaving.`
       }
       Toast.show(errorMessage, {type: 'error'})