refactor(channels): share channel config matching

Co-authored-by: Codex <codex@openai.com>

src/channels/channel-config.ts

@@ -0,0 +1,41 @@
+export type ChannelEntryMatch<T> = {
+  entry?: T;
+  key?: string;
+  wildcardEntry?: T;
+  wildcardKey?: string;
+};
+
+export function buildChannelKeyCandidates(
+  ...keys: Array<string | undefined | null>
+): string[] {
+  const seen = new Set<string>();
+  const candidates: string[] = [];
+  for (const key of keys) {
+    if (typeof key !== "string") continue;
+    const trimmed = key.trim();
+    if (!trimmed || seen.has(trimmed)) continue;
+    seen.add(trimmed);
+    candidates.push(trimmed);
+  }
+  return candidates;
+}
+
+export function resolveChannelEntryMatch<T>(params: {
+  entries?: Record<string, T>;
+  keys: string[];
+  wildcardKey?: string;
+}): ChannelEntryMatch<T> {
+  const entries = params.entries ?? {};
+  const match: ChannelEntryMatch<T> = {};
+  for (const key of params.keys) {
+    if (!Object.prototype.hasOwnProperty.call(entries, key)) continue;
+    match.entry = entries[key];
+    match.key = key;
+    break;
+  }
+  if (params.wildcardKey && Object.prototype.hasOwnProperty.call(entries, params.wildcardKey)) {
+    match.wildcardEntry = entries[params.wildcardKey];
+    match.wildcardKey = params.wildcardKey;
+  }
+  return match;
+}