fix(discord): expose sender bot status in context (#97824)

* fix(discord): expose sender bot status in context

* fix(discord): expose sender bot status in context

---------

Co-authored-by: Vincent Koc <vincentkoc@ieee.org>

extensions/discord/src/monitor/message-handler.context.test.ts

@@ -0,0 +1,44 @@
+// Discord tests cover sender bot-status forwarding into the inbound context payload.
+import { describe, expect, it } from "vitest";
+import { buildDiscordMessageProcessContext } from "./message-handler.context.js";
+import { createBaseDiscordMessageContext } from "./message-handler.test-harness.js";
+
+describe("discord buildDiscordMessageProcessContext sender bot status", () => {
+  it("forwards bot author status to ctxPayload.SenderIsBot", async () => {
+    const ctx = await createBaseDiscordMessageContext({
+      author: { id: "U1", username: "alice", discriminator: "0", globalName: "Alice", bot: true },
+    });
+
+    const result = await buildDiscordMessageProcessContext({ ctx, text: "hi", mediaList: [] });
+    if (!result) {
+      throw new Error("expected a built Discord message context");
+    }
+
+    expect(result.ctxPayload.SenderIsBot).toBe(true);
+  });
+
+  it("omits SenderIsBot for human authors", async () => {
+    const ctx = await createBaseDiscordMessageContext();
+
+    const result = await buildDiscordMessageProcessContext({ ctx, text: "hi", mediaList: [] });
+    if (!result) {
+      throw new Error("expected a built Discord message context");
+    }
+
+    expect(result.ctxPayload.SenderIsBot).toBeUndefined();
+  });
+
+  it("omits SenderIsBot for PluralKit proxy senders despite the bot author", async () => {
+    const ctx = await createBaseDiscordMessageContext({
+      author: { id: "U1", username: "pk", discriminator: "0", globalName: "PK", bot: true },
+      sender: { label: "user", name: "Member", tag: "member", isPluralKit: true },
+    });
+
+    const result = await buildDiscordMessageProcessContext({ ctx, text: "hi", mediaList: [] });
+    if (!result) {
+      throw new Error("expected a built Discord message context");
+    }
+
+    expect(result.ctxPayload.SenderIsBot).toBeUndefined();
+  });
+});

extensions/discord/src/monitor/message-handler.context.ts

@@ -335,6 +335,10 @@ export async function buildDiscordMessageProcessContext(params: {
       tag: sender.tag,
       roles: memberRoleIds,
       displayLabel: senderLabel,
+      // PluralKit proxies post under a bot author but represent a human member,
+      // whose identity already replaced the sender fields here; only mark
+      // genuine (non-PluralKit) bot authors as bots.
+      isBot: author.bot && !sender.isPluralKit ? true : undefined,
     },
     conversation: {
       kind: isDirectMessage ? "direct" : "channel",