fix: preserve timer broadcast after logging

app/services/tournament_transaction_logger.rb

@@ -9,7 +9,9 @@ class TournamentTransactionLogger
         raise 'Tournament transaction log writes must happen inside a transaction'
       end
 
-      tournament.lock!
+      # Lock a fresh row instance so callers keep saved_change_to_* state for
+      # after_commit callbacks on the object they just updated.
+      Tournament.lock.find(tournament.id)
     end
 
     def record!(tournament:, user:, action:, message:, metadata: {})

spec/services/tournament_transaction_logger_spec.rb

@@ -27,5 +27,32 @@ RSpec.describe TournamentTransactionLogger do
       expect(second.sequence).to eq(2)
       expect(tournament.transaction_log_entries.order(:sequence).pluck(:message)).to eq(%w[first second])
     end
+
+    it 'does not clear pending after_commit change tracking on the caller tournament' do
+      tournament = create(:tournament)
+      user = tournament.owner
+      old_timer = { timestamp: nil, timer_mode: nil, timer_reason: nil, timer_reason_text: nil }
+
+      Tournament.transaction do
+        tournament.update!(
+          timestamp: 2.minutes.from_now,
+          timer_mode: 'countdown',
+          timer_reason: 'tournament_start'
+        )
+        new_timer = { timestamp: tournament.timestamp.iso8601, timer_mode: 'countdown',
+                      timer_reason: 'tournament_start', timer_reason_text: nil }
+
+        expect(tournament.saved_change_to_timestamp?).to be(true)
+
+        described_class.record_timer_changed!(
+          tournament: tournament,
+          user: user,
+          old_timer: old_timer,
+          new_timer: new_timer
+        )
+
+        expect(tournament.saved_change_to_timestamp?).to be(true)
+      end
+    end
   end
 end