Add channelAccessTokenConfigured/channelSecretConfigured to ChannelAccountSnapshot type

The LINE channel sets these boolean fields in its status snapshot and uses
them in collectStatusIssues(), but they were missing from the shared
ChannelAccountSnapshot type definition. This caused a type mismatch that
only surfaced at compile time with strict type checking.

src/channels/plugins/types.core.ts

@@ -156,6 +156,8 @@ export type ChannelAccountSnapshot = {
   profile?: unknown;
   channelAccessToken?: string;
   channelSecret?: string;
+  channelAccessTokenConfigured?: boolean;
+  channelSecretConfigured?: boolean;
 };
 
 export type ChannelLogSink = {