Final sweep: Crucible fixes, Path Tracer polish, forge progress, tests green.

Align dashboard subtitle default and UpsertAgent tests with fleet label behavior; WebSocket coalesce and PathForge hardening; Crucible expanded ops and visual DV fixes; Vitest 610/610 and full test-suite pass; trim PROBLEMS.md to open items only.

server/internal/db/sqlite_test.go

@@ -24,6 +24,7 @@ func seedAgent(t *testing.T, d *Database, id string) *models.Agent {
 	a := &models.Agent{
 		ID:       id,
 		Name:     "worker-" + id,
+		Hostname: "worker-" + id,
 		Wallet:   "wallet",
 		IP:       "10.0.0.1",
 		Version:  "2.0",
@@ -74,6 +75,10 @@ func TestUpsertAgentPreservesCreatedAt(t *testing.T) {
 
 	time.Sleep(10 * time.Millisecond)
 	a.Name = "renamed"
+	if a.Hostname == "" {
+		a.Hostname = first.Name
+	}
+	a.Hostname = "renamed"
 	a.Status = "online"
 	if err := d.UpsertAgent(a); err != nil {
 		t.Fatal(err)