fix(progress): always report status transitions and poll for control signals

internal/agent/daemon.go

@@ -6,6 +6,7 @@ import (
 	"log"
 	"os"
 	"runtime"
+	"sync/atomic"
 	"time"
 )
 
@@ -43,7 +44,8 @@ type Daemon struct {
 
 	// Watching tracks whether a user is viewing download progress in the web UI.
 	// When false, the progress reporter skips detailed updates (only sends final states).
-	Watching bool
+	// Accessed from heartbeat goroutine, flush goroutine, and WatchingFunc closure — must be atomic.
+	Watching atomic.Bool
 
 	// Exposed tickers for hot-reload
 	PollTicker      *time.Ticker
@@ -195,7 +197,7 @@ func (d *Daemon) heartbeat(ctx context.Context) {
 	}
 
 	// Update watching flag and state file
-	d.Watching = resp.Watching
+	d.Watching.Store(resp.Watching)
 	d.State.LastHeartbeat = time.Now()
 	if d.GetActiveCount != nil {
 		d.State.ActiveTasks = d.GetActiveCount()

internal/agent/types.go

@@ -109,6 +109,7 @@ type StatusResponse struct {
 	Paused          bool `json:"paused,omitempty"`
 	DeleteFiles     bool `json:"deleteFiles,omitempty"`
 	StreamRequested bool `json:"streamRequested,omitempty"`
+	Watching        bool `json:"watching,omitempty"`
 }
 
 // BatchStatusRequest wraps multiple status updates in a single request.
@@ -118,7 +119,8 @@ type BatchStatusRequest struct {
 
 // BatchStatusResponse wraps per-task results from the batch endpoint.
 type BatchStatusResponse struct {
-	Results []StatusResponse `json:"results"`
+	Results  []StatusResponse `json:"results"`
+	Watching bool             `json:"watching,omitempty"`
 }
 
 // HeartbeatResponse is returned by the server on heartbeat.