fix(collector): publish each repository as its scan finishes

A rescan held every result until the last repository finished. The
dashboard therefore showed new and resolved alerts only at the end.
Each repository now enters the view when its fetch completes. The
last scan time, loaded flag and refresh hooks still update at the end.

internal/collector/collector.go

@@ -155,25 +155,25 @@ func (c *Collector) Refresh(ctx context.Context) {
 	c.limited.Store(false)
 	c.scanDone.Store(0)
 	c.scanTotal.Store(int64(len(c.names)))
-	results := make([]model.Repo, len(c.names))
 	sem := make(chan struct{}, c.concurrency)
 	var wg sync.WaitGroup
-	for i, name := range c.names {
+	for _, name := range c.names {
 		wg.Add(1)
 		sem <- struct{}{}
 		go func() {
 			defer wg.Done()
 			defer func() { <-sem }()
-			results[i] = c.refreshOne(ctx, name, start, true)
+			r := c.refreshOne(ctx, name, start, true)
+			// Publish per repo so a running scan shows new and resolved alerts as they land.
+			c.mu.Lock()
+			c.repos[r.FullName] = r
+			c.mu.Unlock()
 			c.scanDone.Add(1)
 		}()
 	}
 	wg.Wait()
 
 	c.mu.Lock()
-	for _, r := range results {
-		c.repos[r.FullName] = r
-	}
 	c.lastRefresh = start
 	c.lastDur = c.now().Sub(start)
 	c.loaded = true

internal/collector/collector_test.go

@@ -553,3 +553,34 @@ func TestRefreshRepoFailureSkipsRefreshHooks(t *testing.T) {
 	case <-time.After(200 * time.Millisecond):
 	}
 }
+
+func TestRefreshPublishesEachRepoBeforeTheScanEnds(t *testing.T) {
+	release := make(chan struct{})
+	f := &fakeFetcher{fn: func(name string) (model.Repo, error) {
+		if name == "o/slow" {
+			<-release
+		}
+		return model.Repo{FullName: name, Err: ""}, nil
+	}}
+	cfg := &config.Config{Repos: []string{"o/fast", "o/slow"}, RefreshInterval: time.Hour, Concurrency: 2, Thresholds: th()}
+	c := New(f, cfg, slog.New(slog.NewTextHandler(io.Discard, nil)))
+	c.now = func() time.Time { return t0 }
+	done := make(chan struct{})
+	go func() { c.Refresh(context.Background()); close(done) }()
+	deadline := time.Now().Add(2 * time.Second)
+	for time.Now().Before(deadline) {
+		if v := c.View(); len(v.Repos) == 1 && v.Repos[0].FullName == "o/fast" {
+			break
+		}
+		time.Sleep(5 * time.Millisecond)
+	}
+	v := c.View()
+	if len(v.Repos) != 1 || v.Repos[0].FullName != "o/fast" || !v.Refreshing || v.Loaded {
+		t.Fatalf("mid-scan view: repos=%d refreshing=%v loaded=%v", len(v.Repos), v.Refreshing, v.Loaded)
+	}
+	close(release)
+	<-done
+	if v := c.View(); len(v.Repos) != 2 || !v.Loaded {
+		t.Fatalf("after scan: repos=%d loaded=%v", len(v.Repos), v.Loaded)
+	}
+}