fix: capture sendFinalReply return value and document fail-open semantics

Address bot review feedback:
- Use actual sendFinalReply() return for queuedFinal instead of Boolean proxy
- Add JSDoc note about fail-open error semantics for security plugins

Made-with: Cursor

src/auto-reply/reply/dispatch-from-config.ts

@@ -225,14 +225,11 @@ export async function dispatchReplyFromConfig(params: {
       toPluginMessageContext(hookContext),
     );
     if (beforeDispatchResult?.block) {
-      if (beforeDispatchResult.replyText) {
-        dispatcher.sendFinalReply({ text: beforeDispatchResult.replyText });
-      }
+      const queuedFinal = beforeDispatchResult.replyText
+        ? dispatcher.sendFinalReply({ text: beforeDispatchResult.replyText })
+        : false;
       recordProcessed("skipped", { reason: "before_dispatch_blocked" });
-      return {
-        queuedFinal: Boolean(beforeDispatchResult.replyText),
-        counts: dispatcher.getQueuedCounts(),
-      };
+      return { queuedFinal, counts: dispatcher.getQueuedCounts() };
     }
   }
 

src/plugins/hooks.ts

@@ -439,6 +439,11 @@ export function createHookRunner(registry: PluginRegistry, options: HookRunnerOp
    * Allows plugins to block the entire message dispatch before LLM invocation
    * and optionally send a reply text directly to the user.
    * Runs sequentially — first handler that returns { block: true } wins.
+   *
+   * **Error semantics:** Like all hooks, errors are caught and logged when
+   * `catchErrors` is true (the default). This means a throwing handler
+   * results in permit-by-default (fail-open). Security-critical plugins
+   * should handle errors internally to implement fail-closed behavior.
    */
   async function runBeforeDispatch(
     event: PluginHookBeforeDispatchEvent,