feat(#382): Herald Service: broadcast to all active chat providers

- Replace direct DiscordService injection with CHAT_PROVIDERS array
- Herald broadcasts to ALL active chat providers (Discord, Matrix, future)
- Graceful error handling — one provider failure doesn't block others
- Skips disconnected providers automatically
- Tests verify multi-provider broadcasting behavior
- Fix lint: remove unnecessary conditional in matrix.service.ts

Refs #382

apps/api/src/bridge/bridge.module.ts

@@ -1,6 +1,8 @@
 import { Logger, Module } from "@nestjs/common";
 import { DiscordService } from "./discord/discord.service";
 import { MatrixService } from "./matrix/matrix.service";
+import { MatrixRoomService } from "./matrix/matrix-room.service";
+import { CommandParserService } from "./parser/command-parser.service";
 import { StitcherModule } from "../stitcher/stitcher.module";
 import { CHAT_PROVIDERS } from "./bridge.constants";
 import type { IChatProvider } from "./interfaces";
@@ -20,10 +22,15 @@ const logger = new Logger("BridgeModule");
  *
  * Both bridges can run simultaneously, and no error occurs if neither is configured.
  * Consumers should inject CHAT_PROVIDERS for bridge-agnostic access to all active providers.
+ *
+ * CommandParserService provides shared, platform-agnostic command parsing.
+ * MatrixRoomService handles workspace-to-Matrix-room mapping.
  */
 @Module({
   imports: [StitcherModule],
   providers: [
+    CommandParserService,
+    MatrixRoomService,
     DiscordService,
     MatrixService,
     {
@@ -50,6 +57,6 @@ const logger = new Logger("BridgeModule");
       inject: [DiscordService, MatrixService],
     },
   ],
-  exports: [DiscordService, MatrixService, CHAT_PROVIDERS],
+  exports: [DiscordService, MatrixService, MatrixRoomService, CommandParserService, CHAT_PROVIDERS],
 })
 export class BridgeModule {}