Update BotImpl to support instance mode

Add options to BotImpl for integration with Instance:
- federation: Accept an existing Federation instead of creating new one
- skipInitialize: Skip dispatcher/listener registration when managed by Instance

Update InstanceImpl to use these options when creating bots, ensuring
all bots share the same Federation instance.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: moreal

packages/botkit/src/bot-impl.ts

@@ -102,6 +102,16 @@ import type { Text } from "./text.ts";
 export interface BotImplOptions<TContextData>
   extends CreateBotOptions<TContextData> {
   collectionWindow?: number;
+  /**
+   * An existing federation to use instead of creating a new one.
+   * When provided, `skipInitialize` should also be set to `true`.
+   */
+  federation?: Federation<TContextData>;
+  /**
+   * Whether to skip the initialization of the federation.
+   * Set this to `true` when this bot is managed by an Instance.
+   */
+  skipInitialize?: boolean;
 }
 
 export class BotImpl<TContextData> implements Bot<TContextData> {
@@ -159,7 +169,7 @@ export class BotImpl<TContextData> implements Bot<TContextData> {
       css: "",
       ...(options.pages ?? {}),
     };
-    this.federation = createFederation<TContextData>({
+    this.federation = options.federation ?? createFederation<TContextData>({
       kv: options.kv,
       queue: options.queue,
       userAgent: {
@@ -168,7 +178,9 @@ export class BotImpl<TContextData> implements Bot<TContextData> {
     });
     this.behindProxy = options.behindProxy ?? false;
     this.collectionWindow = options.collectionWindow ?? 50;
-    this.initialize();
+    if (!options.skipInitialize) {
+      this.initialize();
+    }
   }
 
   initialize(): void {

packages/botkit/src/instance-impl.ts

@@ -232,6 +232,8 @@ export class InstanceImpl<TContextData> implements Instance<TContextData> {
           behindProxy: this.behindProxy,
           pages: this.pages,
           collectionWindow: this.collectionWindow,
+          federation: this.federation,
+          skipInitialize: true,
         });
         // Copy event handlers from template
         bot.onFollow = template.onFollow;
@@ -619,6 +621,8 @@ export class InstanceImpl<TContextData> implements Instance<TContextData> {
         behindProxy: this.behindProxy,
         pages: this.pages,
         collectionWindow: this.collectionWindow,
+        federation: this.federation,
+        skipInitialize: true,
       });
 
       this.#staticBots.set(identifier, bot);
@@ -639,6 +643,8 @@ export class InstanceImpl<TContextData> implements Instance<TContextData> {
         behindProxy: this.behindProxy,
         pages: this.pages,
         collectionWindow: this.collectionWindow,
+        federation: this.federation,
+        skipInitialize: true,
       });
 
       this.#dynamicDispatchers.push({ dispatcher, template });