feat: add manual video tagging

lib/asr-tags.ts

@@ -38,3 +38,12 @@ export function normalizeAsrContentTags(tags: unknown): AsrContentTag[] {
   const uniqueTags = [...new Set(normalized)].slice(0, 3);
   return uniqueTags.length > 0 ? uniqueTags : ["其他"];
 }
+
+export function resolveEffectiveContentTags(
+  manualTags: readonly string[] | null | undefined,
+  asrTags: readonly string[] | null | undefined,
+) {
+  return manualTags && manualTags.length > 0
+    ? [...manualTags]
+    : [...(asrTags ?? [])];
+}