feat(dashboard): Add dynamic work status column for convoys

The status column now shows computed work status based on progress and activity:
- "complete" (green) - all tracked items are done
- "active" (green) - recent polecat activity (within 1 min)
- "stale" (yellow) - older activity (1-5 min)
- "stuck" (red) - stale activity (5+ min)
- "waiting" (gray) - no assignee/activity

Previously the status column always showed "open" since we only fetch
open convoys, making it static and uninformative.

Changes:
- templates.go: Add WorkStatus field to ConvoyRow, add workStatusClass func
- fetcher.go: Add calculateWorkStatus() to compute status from progress/activity
- convoy.html: Add work status badge styling, use WorkStatus in table

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/web/templates.go

@@ -43,7 +43,8 @@ type MergeQueueRow struct {
 type ConvoyRow struct {
 	ID            string
 	Title         string
-	Status        string // "open" or "closed"
+	Status        string // "open" or "closed" (raw beads status)
+	WorkStatus    string // Computed: "complete", "active", "stale", "stuck", "waiting"
 	Progress      string // e.g., "2/5"
 	Completed     int
 	Total         int
@@ -65,6 +66,7 @@ func LoadTemplates() (*template.Template, error) {
 	funcMap := template.FuncMap{
 		"activityClass":   activityClass,
 		"statusClass":     statusClass,
+		"workStatusClass": workStatusClass,
 		"progressPercent": progressPercent,
 	}
 
@@ -109,6 +111,24 @@ func statusClass(status string) string {
 	}
 }
 
+// workStatusClass returns the CSS class for a computed work status.
+func workStatusClass(workStatus string) string {
+	switch workStatus {
+	case "complete":
+		return "work-complete"
+	case "active":
+		return "work-active"
+	case "stale":
+		return "work-stale"
+	case "stuck":
+		return "work-stuck"
+	case "waiting":
+		return "work-waiting"
+	default:
+		return "work-unknown"
+	}
+}
+
 // progressPercent calculates percentage as an integer for progress bars.
 func progressPercent(completed, total int) int {
 	if total == 0 {