feat(web): connect quick share flow

Signed-off-by: JustMe <mr.toing@outlook.com>

web/src/lib/shareLink.ts

@@ -0,0 +1,29 @@
+import type { LinkError } from './channelLink';
+
+/** 便捷分享的访客链接:`/s/{id}#k={K}`。分享始终是加密模式,没有所有者链接(完成时已丢弃) */
+export interface ParsedShareLink {
+  id: string;
+  /** 解密密钥 K,只放内存 */
+  key: string;
+}
+
+export type ShareLinkResult = { ok: true; link: ParsedShareLink } | { ok: false; error: LinkError };
+
+const ID_RE = /^[A-Za-z0-9_-]{22}$/;
+const KEY_RE = /^[A-Za-z0-9_-]{43}$/;
+
+export function parseShareLink(input: string): ShareLinkResult {
+  let url: URL;
+  try {
+    url = new URL(input.trim());
+  } catch {
+    return { ok: false, error: 'bad_url' };
+  }
+  const m = /^\/s\/([^/]+)\/?$/.exec(url.pathname);
+  if (!m?.[1]) return { ok: false, error: 'bad_url' };
+  if (!ID_RE.test(m[1])) return { ok: false, error: 'bad_id' };
+
+  const key = new URLSearchParams(url.hash.replace(/^#/, '')).get('k');
+  if (key === null || !KEY_RE.test(key)) return { ok: false, error: 'bad_key' };
+  return { ok: true, link: { id: m[1], key } };
+}