supervisor: replace polling with event-driven work assignment

- Add EventBeadReady to eventbus, published by BeadsFS on open/reopen/unclaim
- Wire eventbus into BeadsFS via SetEventBus (called after server init)
- Supervisor now reacts to EventStateChange{idle} and EventBeadReady
  instead of a 5s ticker; 60s fallback ticker retained for safety

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cmd/anvilsrv/main.go

@@ -220,8 +220,9 @@ func start(daemonize bool) {
 	}
 	defer srv.Close()
 
-	// Wire up event bus to session manager
+	// Wire up event bus to session manager and beads filesystem
 	mgr.SetEventBus(srv.Events())
+	beadsFS.SetEventBus(srv.Events())
 
 	// Start maildir writer for message persistence
 	mailDir := filepath.Join(os.Getenv("HOME"), ".local", "share", "anvillm", "mail")

internal/eventbus/bus.go

@@ -19,6 +19,7 @@ const (
 	EventUserSend    = "UserSend"
 	EventBotRecv     = "BotRecv"
 	EventBotSend     = "BotSend"
+	EventBeadReady   = "BeadReady" // a bead transitioned to open/ready
 )
 
 // allTopic is the single topic used for all events.

internal/p9/beads.go

@@ -1,6 +1,7 @@
 package p9
 
 import (
+	"anvillm/internal/eventbus"
 	"anvillm/internal/logging"
 	"context"
 	"encoding/json"
@@ -86,6 +87,7 @@ type BeadsFS struct {
 	queryResult []*bd.Issue
 	mounts      map[string]*MountedProject
 	mountsMu    sync.RWMutex
+	eventbus    *eventbus.Bus
 }
 
 // NewBeadsFS creates a beads filesystem handler from an existing store.
@@ -96,6 +98,18 @@ func NewBeadsFS(store bd.Storage, ctx context.Context) *BeadsFS {
 	}
 }
 
+// SetEventBus wires an event bus for publishing bead state change events.
+func (b *BeadsFS) SetEventBus(eb *eventbus.Bus) {
+	b.eventbus = eb
+}
+
+// publishBeadReady emits EventBeadReady if an event bus is wired.
+func (b *BeadsFS) publishBeadReady(beadID string) {
+	if b.eventbus != nil {
+		b.eventbus.Publish("beads", eventbus.EventBeadReady, map[string]string{"bead_id": beadID})
+	}
+}
+
 // Close is a no-op since the store is managed externally.
 func (b *BeadsFS) Close() error {
 	return nil
@@ -998,7 +1012,11 @@ func (b *BeadsFS) executeCtlOnStore(store bd.Storage, cmd string) error {
 			"assignee": "",
 			"status":   bd.StatusOpen,
 		}
-		return store.UpdateIssue(b.ctx, args[0], updates, actor)
+		if err := store.UpdateIssue(b.ctx, args[0], updates, actor); err != nil {
+			return err
+		}
+		b.publishBeadReady(args[0])
+		return nil
 
 	case "open":
 		// Promote a deferred bead to open (ready for scheduling).
@@ -1006,7 +1024,11 @@ func (b *BeadsFS) executeCtlOnStore(store bd.Storage, cmd string) error {
 		if len(args) < 1 {
 			return fmt.Errorf("usage: open <bead-id>")
 		}
-		return store.UpdateIssue(b.ctx, args[0], map[string]any{"status": bd.StatusOpen}, actor)
+		if err := store.UpdateIssue(b.ctx, args[0], map[string]any{"status": bd.StatusOpen}, actor); err != nil {
+			return err
+		}
+		b.publishBeadReady(args[0])
+		return nil
 
 	case "defer":
 		// Defer a bead, optionally until a specific time (RFC3339).
@@ -1034,7 +1056,11 @@ func (b *BeadsFS) executeCtlOnStore(store bd.Storage, cmd string) error {
 			"status":    bd.StatusOpen,
 			"closed_at": (*time.Time)(nil),
 		}
-		return store.UpdateIssue(b.ctx, args[0], updates, actor)
+		if err := store.UpdateIssue(b.ctx, args[0], updates, actor); err != nil {
+			return err
+		}
+		b.publishBeadReady(args[0])
+		return nil
 
 	case "relate":
 		// Add a bidirectional relates-to dependency between two beads.

internal/supervisor/supervisor.go

@@ -122,20 +122,29 @@ func (s *Supervisor) assignWork() {
 func (s *Supervisor) Run(ctx context.Context) {
 	events, cancel := s.eventbus.Subscribe()
 	defer cancel()
-	ticker := time.NewTicker(5 * time.Second)
-	defer ticker.Stop()
-	syncTicker := time.NewTicker(60 * time.Second)
-	defer syncTicker.Stop()
+	// Fallback ticker: catches anything missed by events (e.g. startup, edge cases).
+	fallback := time.NewTicker(60 * time.Second)
+	defer fallback.Stop()
 	for {
 		select {
 		case <-ctx.Done():
 			return
-		case <-events:
-		case <-ticker.C:
+		case event := <-events:
+			if event == nil {
+				continue
+			}
+			switch event.Type {
+			case eventbus.EventStateChange:
+				// Session went idle — it may be able to take work.
+				if data, ok := event.Data.(map[string]string); ok && data["new_state"] == "idle" {
+					s.assignWork()
+				}
+			case eventbus.EventBeadReady:
+				// A bead just became open/ready — try to assign it.
+				s.assignWork()
+			}
+		case <-fallback.C:
 			s.assignWork()
-		case <-syncTicker.C:
-			// Sync all mounts - need to add accessor method
-			// s.beads.SyncAll()
 		}
 	}
 }