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>

packages/workflow-demo/README.md

@@ -0,0 +1,27 @@
+# Workflow Demo
+
+Interactive demo surface for the example workflow packages.
+
+## Features
+
+- **Workflow cards** — one card per example workflow with description and feature badges
+- **Stage flow diagrams** — visual representation of each workflow's stage progression
+- **Starlark viewer** — collapsible code summary for Starlark-tier packages
+- **API curl examples** — collapsible section with copy-ready curl commands
+- **"Try It" buttons** — launch workflows directly (public link or team start)
+- **Install status** — shows which example workflows are currently installed
+
+## Route
+
+`/s/workflow-demo` — accessible to any authenticated user.
+
+## Installation
+
+Install alongside the example workflow packages. The demo surface detects which
+workflows are installed and shows their status accordingly.
+
+```bash
+curl -X POST $BASE/api/v1/admin/packages/install \
+  -H "Authorization: Bearer $TOKEN" \
+  -F "file=@packages/workflow-demo"
+```