Extract a default prompt

docs/architecture.md

@@ -129,6 +129,7 @@ Last.fm schemas (separate, not Ecto-persisted to main DB):
 | `Chats.StreamProvider` | Behaviour for streaming AI chat (`stream_response/3` callback) |
 | `Chats.RecordChat` | Chat implementation for records (OpenAI streaming, web search enabled) |
 | `Chats.ArtistChat` | Chat implementation for artists (OpenAI streaming, uses Wikipedia/artist context) |
+| `Chats.DefaultPrompt` | Shared default prompt fragments (identity, approach) for chat implementations |
 | `Country` | Country code (alpha-2, alpha-3, subdivision, IETF) to flag emoji conversion |
 | `ErrorTracker.ErrorNotifier` | GenServer: attaches to ErrorTracker telemetry, skips muted errors, throttles repeated errors, dispatches email notifications |
 | `ErrorTracker.ErrorNotifier.Email` | Builds and sends Swoosh error notification emails with stack trace formatting |

lib/music_library/chats/artist_chat.ex

@@ -6,6 +6,7 @@ defmodule MusicLibrary.Chats.ArtistChat do
   @behaviour MusicLibrary.Chats.StreamProvider
 
   alias MusicLibrary.Artists.ArtistInfo
+  alias MusicLibrary.Chats.DefaultPrompt
 
   @impl true
   @spec stream_response([map()], {map(), ArtistInfo.t()}, (String.t() -> any())) ::
@@ -20,17 +21,13 @@ defmodule MusicLibrary.Chats.ArtistChat do
     context = build_context(artist, artist_info)
 
     """
-    You are a knowledgeable music assistant. Answer questions about the artist \
-    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. \
-    Include links when they add genuine value, but not on every response.
+    #{DefaultPrompt.identity()}
+    Answer questions about the artist the user is currently viewing. \
+    Use the provided artist information as your primary reference, \
 
-    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.
+    #{DefaultPrompt.approach()}
 
-    Artist information:
+    Album information:
     #{context}
     """
   end

lib/music_library/chats/default_prompt.ex

@@ -0,0 +1,21 @@
+defmodule MusicLibrary.Chats.DefaultPrompt do
+  @moduledoc false
+
+  def identity do
+    """
+    You are a knowledgeable music assistant.
+    """
+  end
+
+  def approach do
+    """
+    Use web search to find additional up-to-date \
+    information when helpful. Be concise and accurate. When unsure, say so. \
+    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.
+    """
+  end
+end

lib/music_library/chats/record_chat.ex

@@ -5,6 +5,7 @@ defmodule MusicLibrary.Chats.RecordChat do
 
   @behaviour MusicLibrary.Chats.StreamProvider
 
+  alias MusicLibrary.Chats.DefaultPrompt
   alias MusicLibrary.Records.Record
 
   @impl true
@@ -25,15 +26,11 @@ defmodule MusicLibrary.Chats.RecordChat do
       end
 
     """
-    You are a knowledgeable music assistant. Answer questions about the album \
-    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. \
-    Include links when they add genuine value, but not on every response.
+    #{DefaultPrompt.identity()}
+    Answer questions about the album the user is currently viewing. \
+    Use the provided album information as your primary reference, \
 
-    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.
+    #{DefaultPrompt.approach()}
 
     Album information:
     #{context}