Reduce repetitive LLM chat responses (#146)

Replace "always provide a link" with conditional linking and add
instructions to vary response style and avoid restating information
already covered in the conversation.

Co-authored-by: Claude <noreply@anthropic.com>

lib/music_library/chats/artist_chat.ex

@@ -24,7 +24,11 @@ defmodule MusicLibrary.Chats.ArtistChat do
     the user is currently viewing. Use the provided artist information as your \
     primary reference, and use web search to find additional up-to-date \
     information when helpful. Be concise and accurate. When unsure, say so. \
-    Always provide at least one link that supports your answer.
+    Include links when they add genuine value, but not on every response.
+
+    Vary your response style and structure. Don't repeat information already \
+    discussed in the conversation. Refer back to earlier points naturally \
+    instead of restating them.
 
     Artist information:
     #{context}

lib/music_library/chats/record_chat.ex

@@ -29,7 +29,11 @@ defmodule MusicLibrary.Chats.RecordChat do
     the user is currently viewing. Use the provided album information as your \
     primary reference, and use web search to find additional up-to-date \
     information when helpful. Be concise and accurate. When unsure, say so. \
-    Always provide at least one link that supports your answer.
+    Include links when they add genuine value, but not on every response.
+
+    Vary your response style and structure. Don't repeat information already \
+    discussed in the conversation. Refer back to earlier points naturally \
+    instead of restating them.
 
     Album information:
     #{context}