fix: chatd refactor (#26270)

Implements the chatd stabilization RFC.

Combines:
- https://github.com/coder/coder/pull/25908
- https://github.com/coder/coder/pull/25923
- https://github.com/coder/coder/pull/26109
- https://github.com/coder/coder/pull/26110
- https://github.com/coder/coder/pull/26111
- https://github.com/coder/coder/pull/26112

coderd/x/chatd/chatdebug/service.go

@@ -522,6 +522,60 @@ func (s *Service) TouchStep(
 		})
 }
 
+// TouchRun bumps the run's updated_at timestamp without changing any
+// other fields. Runner-owned debug turns use this while no model step is
+// active, such as requires-action waits.
+func (s *Service) TouchRun(ctx context.Context, runID uuid.UUID, chatID uuid.UUID) error {
+	if s == nil || runID == uuid.Nil || chatID == uuid.Nil {
+		return nil
+	}
+	return s.db.TouchChatDebugRunUpdatedAt(chatdContext(ctx),
+		database.TouchChatDebugRunUpdatedAtParams{
+			Now:    s.clock.Now(),
+			ID:     runID,
+			ChatID: chatID,
+		})
+}
+
+// LaunchRunHeartbeat starts a goroutine that periodically touches an
+// open run until done is closed or ctx is canceled.
+func (s *Service) LaunchRunHeartbeat(ctx context.Context, runID uuid.UUID, chatID uuid.UUID, done <-chan struct{}) {
+	if s == nil || runID == uuid.Nil || chatID == uuid.Nil || done == nil {
+		return
+	}
+	go func() {
+		thresholdCh := s.thresholdChan()
+		interval := s.heartbeatInterval()
+		ticker := s.clock.NewTicker(interval, "chatdebug", "run-heartbeat")
+		defer ticker.Stop()
+		resetTicker := func() {
+			if newInterval := s.heartbeatInterval(); newInterval != interval {
+				interval = newInterval
+				ticker.Reset(interval, "chatdebug", "run-heartbeat")
+			}
+		}
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case <-done:
+				return
+			case <-thresholdCh:
+				thresholdCh = s.thresholdChan()
+				resetTicker()
+			case <-ticker.C:
+				if err := s.TouchRun(ctx, runID, chatID); err != nil {
+					s.log.Debug(ctx, "run heartbeat touch failed",
+						slog.Error(err),
+						slog.F("run_id", runID),
+					)
+				}
+				resetTicker()
+			}
+		}
+	}()
+}
+
 // DeleteByChatID deletes debug data for a chat and emits a delete event.
 // The startedBefore bound scopes deletion to runs created before that
 // instant so that retried cleanup does not remove runs created by a

coderd/x/chatd/chatdebug/summary.go

@@ -41,28 +41,6 @@ func SeedSummary(label string) map[string]any {
 	return map[string]any{"first_message": label}
 }
 
-// ExtractFirstUserText extracts the plain text content from a
-// fantasy.Prompt for the first user message. Used to derive
-// first_message labels at run creation time.
-func ExtractFirstUserText(prompt fantasy.Prompt) string {
-	for _, msg := range prompt {
-		if msg.Role != fantasy.MessageRoleUser {
-			continue
-		}
-
-		var sb strings.Builder
-		for _, part := range msg.Content {
-			tp, ok := fantasy.AsMessagePart[fantasy.TextPart](part)
-			if !ok {
-				continue
-			}
-			_, _ = sb.WriteString(tp.Text)
-		}
-		return sb.String()
-	}
-	return ""
-}
-
 // AggregateRunSummary reads all steps for the given run, computes token
 // totals, and merges them with the run's existing summary (preserving any
 // seeded first_message label). The baseSummary parameter should be the

coderd/x/chatd/chatdebug/summary_test.go

@@ -6,7 +6,6 @@ import (
 	"time"
 	"unicode/utf8"
 
-	"charm.land/fantasy"
 	"github.com/google/uuid"
 	"github.com/sqlc-dev/pqtype"
 	"github.com/stretchr/testify/require"
@@ -62,68 +61,6 @@ func TestSeedSummary(t *testing.T) {
 	})
 }
 
-func TestExtractFirstUserText(t *testing.T) {
-	t.Parallel()
-
-	t.Run("EmptyPrompt", func(t *testing.T) {
-		t.Parallel()
-		got := chatdebug.ExtractFirstUserText(fantasy.Prompt{})
-		require.Equal(t, "", got)
-	})
-
-	t.Run("NoUserMessages", func(t *testing.T) {
-		t.Parallel()
-		prompt := fantasy.Prompt{
-			{
-				Role:    fantasy.MessageRoleSystem,
-				Content: []fantasy.MessagePart{fantasy.TextPart{Text: "system"}},
-			},
-			{
-				Role:    fantasy.MessageRoleAssistant,
-				Content: []fantasy.MessagePart{fantasy.TextPart{Text: "assistant"}},
-			},
-		}
-		got := chatdebug.ExtractFirstUserText(prompt)
-		require.Equal(t, "", got)
-	})
-
-	t.Run("FirstUserMessageMixedParts", func(t *testing.T) {
-		t.Parallel()
-		prompt := fantasy.Prompt{
-			{
-				Role: fantasy.MessageRoleUser,
-				Content: []fantasy.MessagePart{
-					fantasy.TextPart{Text: "hello "},
-					fantasy.FilePart{Filename: "test.png"},
-					fantasy.TextPart{Text: "world"},
-				},
-			},
-		}
-		got := chatdebug.ExtractFirstUserText(prompt)
-		require.Equal(t, "hello world", got)
-	})
-
-	t.Run("MultipleUserMessagesReturnsFirst", func(t *testing.T) {
-		t.Parallel()
-		prompt := fantasy.Prompt{
-			{
-				Role:    fantasy.MessageRoleSystem,
-				Content: []fantasy.MessagePart{fantasy.TextPart{Text: "system"}},
-			},
-			{
-				Role:    fantasy.MessageRoleUser,
-				Content: []fantasy.MessagePart{fantasy.TextPart{Text: "first"}},
-			},
-			{
-				Role:    fantasy.MessageRoleUser,
-				Content: []fantasy.MessagePart{fantasy.TextPart{Text: "second"}},
-			},
-		}
-		got := chatdebug.ExtractFirstUserText(prompt)
-		require.Equal(t, "first", got)
-	})
-}
-
 func TestService_AggregateRunSummary(t *testing.T) {
 	t.Parallel()