feat(domain): progress steps and the two timestamps that tell alive from progressing (ADR-035)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/domain/domain.go

@@ -175,6 +175,32 @@ type Reconciliation struct {
 	Contested    []ContestedSpot `json:"contested,omitempty"`
 }
 
+// StepState is where one phase of an upload job stands (ADR-035).
+type StepState string
+
+const (
+	StepPending StepState = "pending"
+	StepRunning StepState = "running"
+	StepDone    StepState = "done"
+	StepFailed  StepState = "failed"
+	// StepSkipped is a step that never ran because the job finished without it, for
+	// example the second engine's step when the first engine's text was used alone.
+	StepSkipped StepState = "skipped"
+)
+
+// ProgressStep is one named phase of an upload job. Total is zero for a phase with no
+// count; only a phase whose work is really countable carries one (ADR-035: no
+// percentage that does not come from real counts).
+type ProgressStep struct {
+	Key        string    `json:"key"`
+	Label      string    `json:"label"`
+	State      StepState `json:"state"`
+	StartedAt  time.Time `json:"started_at,omitzero"`
+	FinishedAt time.Time `json:"finished_at,omitzero"`
+	Done       int       `json:"done,omitempty"`
+	Total      int       `json:"total,omitempty"`
+}
+
 // UploadStatus is the state of an uploaded-audio transcription job.
 type UploadStatus string
 
@@ -218,6 +244,13 @@ type UploadedTranscript struct {
 	// Reconciliation is how a merged transcript came about, or nil for a single
 	// engine (ADR-034). Set by Get, not by List.
 	Reconciliation *Reconciliation
-	CreatedAt      time.Time
-	FinishedAt     time.Time // zero until the job reaches done or failed
+	// Progress is the job's phases, in order. Set by Get, not by List (ADR-035).
+	Progress []ProgressStep
+	// ProgressAt is when a phase last really changed or advanced; AliveAt is the
+	// heartbeat. They differ on purpose: alive says the service is still reporting,
+	// progress says work is moving (ADR-035). Both are zero until the job starts.
+	ProgressAt time.Time
+	AliveAt    time.Time
+	CreatedAt  time.Time
+	FinishedAt time.Time // zero until the job reaches done or failed
 }