feat: add chunking mode for outbound messages

- Introduced `chunkMode` option in various account configurations to allow splitting messages by "length" or "newline".
- Updated message processing to handle chunking based on the selected mode.
- Added tests for new chunking functionality, ensuring correct behavior for both modes.

extensions/nextcloud-talk/src/config-schema.ts

@@ -44,6 +44,7 @@ export const NextcloudTalkAccountSchemaBase = z
     dmHistoryLimit: z.number().int().min(0).optional(),
     dms: z.record(z.string(), DmConfigSchema.optional()).optional(),
     textChunkLimit: z.number().int().positive().optional(),
+    chunkMode: z.enum(["length", "newline"]).optional(),
     blockStreaming: z.boolean().optional(),
     blockStreamingCoalesce: BlockStreamingCoalesceSchema.optional(),
     mediaMaxMb: z.number().positive().optional(),

extensions/nextcloud-talk/src/types.ts

@@ -62,6 +62,8 @@ export type NextcloudTalkAccountConfig = {
   dms?: Record<string, DmConfig>;
   /** Outbound text chunk size (chars). Default: 4000. */
   textChunkLimit?: number;
+  /** Chunking mode: "length" (default) splits by size, "newline" splits on every newline. */
+  chunkMode?: "length" | "newline";
   /** Disable block streaming for this account. */
   blockStreaming?: boolean;
   /** Merge streamed block replies before sending. */