feat: Integrations splits into Library, Acquisition, Metadata sources and Email & network, each a page on the admin rail; the Overview keeps only what needs you (M503 #5607)

- Library: the folders, Run scan and a row per scan job, cover art, fingerprints and loudness (off the Overview and Duplicates)
- Acquisition: indexers and clients, searching, re-acquisition (off Missing files), Lidarr
- Metadata sources: AcoustID, and one provider block for cover art and tags in place of the pasted pair
- Email & network: outgoing email, the notification schedule, public address, proxies
- Lidarr, outgoing email and the provider block are rebuilt as SettingsGroup rows; failures read as sentences, not codes
- Duplicates and Missing files say what their setting is and link to where it is set

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/lib/components/ReacquisitionSettingsCard.svelte

@@ -10,9 +10,9 @@
   import { pushToast } from '#lib/stores/toast.svelte.js';
 
   // Policy for putting an album whose files went missing back on the wanted
-  // list (milestone #290, M502 #5520). Lives on the missing-files page rather
-  // than under Integrations because this is where the operator meets the
-  // problem it solves. Searching for a want, and retrying, is the search
+  // list (milestone #290, M502 #5520). On Admin › Acquisition with the rest
+  // of how music is got (#5607); Missing files says what it is set to and
+  // links here. Searching for a want, and retrying, is the search
   // schedule's job, so there is no retry policy here.
 
   let saved = $state<ReacquisitionSettings | null>(null);