refactor: dedupe tlon and voice-call lowercase helpers

src/channels/conversation-label.ts

@@ -1,5 +1,8 @@
 import type { MsgContext } from "../auto-reply/templating.js";
-import { normalizeOptionalString } from "../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalString,
+} from "../shared/string-coerce.js";
 import { normalizeChatType } from "./chat-type.js";
 
 function extractConversationId(from?: string): string | undefined {
@@ -60,7 +63,7 @@ export function resolveConversationLabel(ctx: MsgContext): string | undefined {
   if (base.includes(id)) {
     return base;
   }
-  if (base.toLowerCase().includes(" id:")) {
+  if (normalizeLowercaseStringOrEmpty(base).includes(" id:")) {
     return base;
   }
   if (base.startsWith("#") || base.startsWith("@")) {

src/channels/plugins/chat-target-prefixes.ts

@@ -1,3 +1,5 @@
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
+
 export type ServicePrefix<TService extends string> = { prefix: string; service: TService };
 
 export type ChatTargetPrefixesParams = {
@@ -94,7 +96,7 @@ export function resolveServicePrefixedTarget<TService extends string, TTarget>(p
     if (!remainder) {
       throw new Error(`${prefix} target is required`);
     }
-    const remainderLower = remainder.toLowerCase();
+    const remainderLower = normalizeLowercaseStringOrEmpty(remainder);
     if (params.isChatTarget(remainderLower)) {
       return params.parseTarget(remainder);
     }