feat: IRC — add first-class channel support

Adds IRC as a first-class channel with core config surfaces (schema/hints/dock), plugin auto-enable detection, routing/policy alignment, and docs/tests.

Co-authored-by: Vignesh <vigneshnatarajan92@gmail.com>

src/config/types.ts

@@ -14,6 +14,7 @@ export * from "./types.googlechat.js";
 export * from "./types.gateway.js";
 export * from "./types.hooks.js";
 export * from "./types.imessage.js";
+export * from "./types.irc.js";
 export * from "./types.messages.js";
 export * from "./types.models.js";
 export * from "./types.node-host.js";