Fix deployment failure by updating outdated references (#96)

Issue #46

Production deployments were failing because `ConversationDetector` was
trying to load a file that no longer exists. When I renamed the digest
feature to feed, I missed updating the references in
`conversation_detector.rb`.

This fixes the `LoadError` by:
- Removing require for `digest_prompts.rb` and using `feed_prompts.rb`
instead
- Updating all `DigestPrompts` module references to `FeedPrompts`
- Renaming `digested_count` variable to `in_feed_count` for consistency
- Cleaning up outdated comments that still referenced digest terminology

The container health checks were failing because Rails couldn't load the
`ConversationDetector` service. This should allow the application to
start successfully in production.

Tested locally with Docker.

Author: gianfrancopiana

app/models/message.rb

@@ -184,8 +184,6 @@ def broadcast_parent_message_to_threads
   end
 
   def deactivate_copied_messages_on_deactivation
-    # When an original message is deactivated/reactivated, sync the state to all copied messages
-    # This ensures digest/conversation rooms reflect the current state of messages in the source room
     if saved_change_to_attribute?(:active) && copied_messages.any?
       copied_messages.update_all(active: active)
     end

app/services/automated_feed/scanner.rb

@@ -127,7 +127,7 @@ def excluded_room_ids
 
     def log_scan(messages)
       if room.present?
-        digested_count = messages.count(&:in_feed?)
+        in_feed_count = messages.count(&:in_feed?)
         recent_count = messages.count { |m| m.created_at >= room_scan_lookback_start }
         old_count = messages.size - recent_count
 
@@ -137,7 +137,7 @@ def log_scan(messages)
         Rails.logger.info "[AutomatedFeed::Scanner] Scanning #{messages.size} messages from room ##{room.id} (#{room.name})"
         Rails.logger.info "[AutomatedFeed::Scanner]   - Recent (last 12h): #{recent_count} messages"
         Rails.logger.info "[AutomatedFeed::Scanner]   - Backlog/context: #{old_count} messages"
-        Rails.logger.info "[AutomatedFeed::Scanner]   - Already in feed: #{digested_count} messages"
+        Rails.logger.info "[AutomatedFeed::Scanner]   - Already in feed: #{in_feed_count} messages"
         Rails.logger.info "[AutomatedFeed::Scanner]   - Time range: #{oldest_msg&.created_at&.strftime('%Y-%m-%d %H:%M')} to #{newest_msg&.created_at&.strftime('%Y-%m-%d %H:%M')}" if oldest_msg && newest_msg
       else
         Rails.logger.info "[AutomatedFeed::Scanner] Scanning #{messages.size} non-feed messages from last #{@config.lookback_hours} hours"

app/services/conversation_detector.rb

@@ -1,5 +1,4 @@
 require_relative "ai_gateway"
-require_relative "digest_prompts"
 require_relative "feed_prompts"
 
 class ConversationDetector
@@ -148,7 +147,7 @@ def format_messages_for_ai
       - "thread-reply-to-X" = reply in thread under message X
 
       TASK:
-      #{DigestPrompts.conversation_completeness_instructions}
+      #{FeedPrompts.conversation_completeness_instructions}
       
       OUTPUT FORMAT (JSON):
       {
@@ -277,13 +276,13 @@ def generate_title_and_summary
 
       REQUIREMENTS:
 
-      #{DigestPrompts.title_guidelines}
+      #{FeedPrompts.title_guidelines}
 
-      #{DigestPrompts.summary_guidelines}
+      #{FeedPrompts.summary_guidelines}
 
-      #{DigestPrompts.key_insight_guidelines}
+      #{FeedPrompts.key_insight_guidelines}
 
-      #{DigestPrompts.preview_message_guidelines}
+      #{FeedPrompts.preview_message_guidelines}
 
       TONE GUIDE:
       - Write like a human, not a corporate blog

test/services/automated_feed/deduplicator_test.rb

@@ -131,7 +131,7 @@ class DeduplicatorTest < ActiveSupport::TestCase
         creator: @user1
       )
 
-      # Create digest cards for each
+      # Create feed cards for each
       card_from_room_1 = AutomatedFeedCard.create!(
         room: conv_room_1,
         title: "Card from room 1",