feat(servers/settings): magic string invites, Navidrome admin share, and add-user validation (#258)

* feat(servers): magic string invites and duplicate-aware labels

Add psysonic1- share payloads (URL, Subsonic credentials, optional server
name). Login and add-server forms decode on input and keep magic field
below standard fields. Navidrome User Management generates strings after
PUT password updates where required. Resolve duplicate display names as
username@host in chrome, settings, and login.

* feat(servers): tighten magic-string import and admin share flow

After a decoded magic string, username is read-only and the password field
shows a fixed-length mask so length is not inferred. Password reveal stays
disabled until saved-server quick connect (login) or reopening the add-
server form. Navidrome admin share UI persists the password via API before
copy and adds a plaintext-handling disclaimer. Locales updated.

* feat(settings): save new Navidrome user and copy magic string

Add a non-admin "Save and get magic string" flow: create the user, assign
libraries when needed, then encode credentials to the clipboard. Reuse
the plaintext-handling disclaimer without the password-update hint meant
for edits. Strings added for all locales.

* fix(settings): tighten Navidrome add-user validation and submit feedback

Require username, display name, and a non-empty password (trimmed) for new
users; gate Save and “save and get magic string” on explicit checks with
toast feedback. Show red borders only after a failed submit, and clear
them when the user fills the fields. When editing, keep an empty password
as “unchanged” and validate identity fields with a dedicated message.
Strings: userMgmtValidationMissingIdentity across locales.

src/utils/serverDisplayName.ts

@@ -0,0 +1,36 @@
+import type { ServerProfile } from '../store/authStore';
+
+/** Host (+ port) from a server base URL, e.g. `https://music.one.com/foo` → `music.one.com`. */
+export function shortHostFromServerUrl(urlRaw: string): string {
+  const t = urlRaw.trim();
+  if (!t) return '';
+  try {
+    const u = new URL(t.includes('://') ? t : `https://${t}`);
+    return u.host;
+  } catch {
+    return t
+      .replace(/^https?:\/\//i, '')
+      .split('/')[0]
+      ?.split('?')[0]
+      ?.trim() ?? t;
+  }
+}
+
+/**
+ * Label for server lists and chrome: if several servers share the same effective name,
+ * show `username@host` so entries stay distinguishable.
+ */
+export function serverListDisplayLabel(server: ServerProfile, all: ServerProfile[]): string {
+  const nameTrim = (server.name || '').trim();
+  const shortHost = shortHostFromServerUrl(server.url);
+  const key = nameTrim || shortHost;
+  const collisions = all.filter(s => {
+    const nt = (s.name || '').trim();
+    const sh = shortHostFromServerUrl(s.url);
+    return (nt || sh) === key;
+  });
+  if (collisions.length < 2) {
+    return nameTrim || shortHost || server.url.trim();
+  }
+  return `${server.username}@${shortHost}`;
+}