fix: newline chunking across channels

src/config/types.msteams.ts

@@ -72,6 +72,8 @@ export type MSTeamsConfig = {
   groupPolicy?: GroupPolicy;
   /** Outbound text chunk size (chars). Default: 4000. */
   textChunkLimit?: number;
+  /** Chunking mode: "length" (default) splits by size; "newline" splits on every newline. */
+  chunkMode?: "length" | "newline";
   /** Merge streamed block replies before sending. */
   blockStreamingCoalesce?: BlockStreamingCoalesceConfig;
   /**