fix: never split replies into multiple messages (Fabric has no length limit)

Unlike Discord, Fabric has no message-length cap. Single-chunk chunker
(text -> [text]), textChunkLimit=MAX_SAFE_INTEGER, capabilities
blockStreaming=false, replyOptions.disableBlockStreaming=true -> every
agent reply delivered as exactly one Fabric message.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/channel.ts

@@ -105,7 +105,9 @@ export const fabricChannelPlugin = createChatChannelPlugin<ResolvedFabricAccount
       threads: false,
       media: false,
       nativeCommands: false,
-      blockStreaming: true,
+      // Fabric has no message-length limit and we never want a reply split
+      // into multiple messages -> no block streaming.
+      blockStreaming: false,
     },
     reload: { configPrefixes: ['channels.fabric'] },
     config: {
@@ -142,7 +144,12 @@ export const fabricChannelPlugin = createChatChannelPlugin<ResolvedFabricAccount
   threading: { topLevelReplyToMode: 'channel' },
 
   outbound: {
-    base: {},
+    base: {
+      deliveryMode: 'direct',
+      // Fabric has no length limit: never chunk — always one message.
+      chunker: (text: string) => [text],
+      textChunkLimit: Number.MAX_SAFE_INTEGER,
+    },
     attachedResults: {
       channel: 'fabric',
       sendText: async (ctx: {

src/inbound.ts

@@ -176,7 +176,8 @@ export class FabricInbound {
           this.log.warn(`fabric: session record failed agent=${agentId}: ${String(err)}`),
         onDispatchError: (err: unknown, info: { kind: string }) =>
           this.log.warn(`fabric: ${info.kind} dispatch failed agent=${agentId}: ${String(err)}`),
-        replyOptions: {},
+        // Fabric has no length limit: deliver the whole reply as ONE message.
+        replyOptions: { disableBlockStreaming: true } as never,
       });
       this.log.info(`fabric: dispatch returned agent=${agentId} channel=${channelId}`);
     } catch (err) {