Fix Amazon missing from _get_enrichment_status workers_info

_get_enrichment_status had a hardcoded workers_info list. Amazon was
registered in the generic enrichment blueprint but never added here,
so the rate-monitor speedometer overlay and status API omitted it.

Adds ('amazon_enrichment', 'Amazon Music', lambda: amazon_worker)
to workers_info — same pattern as Deezer, Discogs, Tidal, Qobuz.

web_server.py

@@ -2005,6 +2005,7 @@ def _get_enrichment_status():
         ('genius', 'Genius', lambda: genius_worker),
         ('audiodb', 'AudioDB', lambda: audiodb_worker),
         ('discogs', 'Discogs', lambda: discogs_worker),
+        ('amazon_enrichment', 'Amazon Music', lambda: amazon_worker),
     ]
 
     # Config-based "configured" checks for services that need API keys/credentials