Feat v0.3.6 demo workflows + interactive demo

Four example workflow packages proving the engine end-to-end:
- Bug Report Triage: public entry, branch routing, SLA timer
- Employee Onboarding: Starlark automated stages, signoff gate
- Content Approval: multi-party signoff, revision cycle loop
- Webhook Notifier: http.post, connections fallback, delivery logging

Demo surface at /s/workflow-demo with cards, stage diagrams, Starlark
viewer, API examples, active/published status, and copyable public links.

Engine fixes: started_by in automated context, sla_seconds in package
installer, parseSnapshotStages for wrapped/legacy formats.

Platform fixes: extension SDK boot in base.html (Preact globals + boot()),
admin teams paginated response extraction, workflow adoption endpoint
(POST /teams/:teamId/workflows/:id/adopt), team-admin copyable link.

Review pass remains on roadmap for remaining UI polish.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/workflow/scanner.go

@@ -91,8 +91,8 @@ func (sc *Scanner) runScan() {
 		if err != nil {
 			return nil
 		}
-		var stages []models.WorkflowStage
-		if json.Unmarshal(v.Snapshot, &stages) != nil {
+		stages, parseErr := parseSnapshotStages(v.Snapshot)
+		if parseErr != nil {
 			return nil
 		}
 		versionCache[key] = stages