refactor: centralize target normalization

src/infra/outbound/target-normalization.ts

@@ -0,0 +1,31 @@
+import { getChannelPlugin, normalizeChannelId } from "../../channels/plugins/index.js";
+import type { ChannelId } from "../../channels/plugins/types.js";
+
+export function normalizeChannelTargetInput(raw: string): string {
+  return raw.trim();
+}
+
+export function normalizeTargetForProvider(provider: string, raw?: string): string | undefined {
+  if (!raw) return undefined;
+  const providerId = normalizeChannelId(provider);
+  const plugin = providerId ? getChannelPlugin(providerId) : undefined;
+  const normalized =
+    plugin?.messaging?.normalizeTarget?.(raw) ?? (raw.trim().toLowerCase() || undefined);
+  return normalized || undefined;
+}
+
+export function buildTargetResolverSignature(channel: ChannelId): string {
+  const plugin = getChannelPlugin(channel);
+  const hint = plugin?.messaging?.targetHint ?? "";
+  const looksLike = plugin?.messaging?.looksLikeTargetId;
+  const source = looksLike ? looksLike.toString() : "";
+  return hashSignature(`${hint}|${source}`);
+}
+
+function hashSignature(value: string): string {
+  let hash = 5381;
+  for (let i = 0; i < value.length; i += 1) {
+    hash = ((hash << 5) + hash) ^ value.charCodeAt(i);
+  }
+  return (hash >>> 0).toString(36);
+}