test(adapters): adopt shared @chat-adapter/tests factories and matchers (#674)

Wires `@chat-adapter/tests` as a devDependency and registers its
matchers via `setupFiles: ["@chat-adapter/tests/setup"]` across all 11
platform adapters, then replaces bespoke local
`mockLogger`/`createMockState`/`createMockChatInstance` with the shared
factories and adopts `toHaveDispatched`/`not.toHaveDispatched` where
clean.

- 10 adapters migrated (gchat, messenger, teams, whatsapp, telegram,
discord, twilio, linear, github, slack). Positional
`createMockChatInstance(...)` call sites converted to the options API
(slack 100, linear 35).
- `web` left as-is — its suite uses the real `Chat`/`createMemoryState`
for e2e, so the shared factories don't apply.
- Platform SDK mocks (Octokit, WebClient, socket-mode, `@linear/sdk`,
`fetch`) and the Phase 1 `connectWebhookContract` descriptors are left
intact.

Net ~−540 lines of duplicated test scaffolding. Stacked on #673.
Tests-only, no changeset.

---------

Signed-off-by: Ben Sabic <bensabic@users.noreply.github.com>
Co-authored-by: Ben Sabic <bensabic@users.noreply.github.com>

Author: bensabic

packages/adapter-discord/package.json

@@ -34,6 +34,7 @@
     "discord.js": "^14.25.1"
   },
   "devDependencies": {
+    "@chat-adapter/tests": "workspace:*",
     "@types/node": "^25.3.2",
     "tsup": "^8.3.5",
     "typescript": "^5.7.2",

packages/adapter-discord/src/gateway.test.ts

@@ -5,6 +5,7 @@
  * intents and partials for receiving DM events.
  */
 
+import { createMockChatInstance, mockLogger } from "@chat-adapter/tests";
 import { GatewayIntentBits, Partials } from "discord.js";
 import { describe, expect, it, vi } from "vitest";
 import { createDiscordAdapter } from "./index";
@@ -33,30 +34,6 @@ vi.mock("discord.js", async () => {
   };
 });
 
-const mockLogger = {
-  debug: vi.fn(),
-  info: vi.fn(),
-  warn: vi.fn(),
-  error: vi.fn(),
-  child: vi.fn().mockReturnThis(),
-};
-
-const mockChat = {
-  getLogger: vi.fn().mockReturnValue(mockLogger),
-  getState: vi.fn(),
-  getUserName: vi.fn().mockReturnValue("bot"),
-  handleIncomingMessage: vi.fn(),
-  processAction: vi.fn(),
-  processOptionsLoad: vi.fn().mockResolvedValue(undefined),
-  processAppHomeOpened: vi.fn(),
-  processAssistantContextChanged: vi.fn(),
-  processAssistantThreadStarted: vi.fn(),
-  processMessage: vi.fn(),
-  processModalClose: vi.fn(),
-  processModalSubmit: vi.fn(),
-  processReaction: vi.fn(),
-};
-
 describe("Gateway client configuration", () => {
   it("includes Partials.Channel for DM support", async () => {
     MockClient.mockClear();
@@ -71,7 +48,7 @@ describe("Gateway client configuration", () => {
       logger: mockLogger,
     });
 
-    await adapter.initialize(mockChat as never);
+    await adapter.initialize(createMockChatInstance());
 
     // Use a pre-aborted signal so the listener resolves immediately
     const controller = new AbortController();