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/handlers/workflow_team.go

@@ -37,6 +37,53 @@ func (h *WorkflowHandler) requireTeamWorkflow(c *gin.Context) bool {
 	return true
 }
 
+// ── Adopt Global Workflow ────────────────────
+
+// AdoptTeamWorkflow claims a global (team_id=NULL) workflow for this team.
+// POST /api/v1/teams/:teamId/workflows/:id/adopt
+func (h *WorkflowHandler) AdoptTeamWorkflow(c *gin.Context) {
+	teamID := c.Param("teamId")
+	wfID := c.Param("id")
+
+	w, err := h.stores.Workflows.GetByID(c.Request.Context(), wfID)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			c.JSON(http.StatusNotFound, gin.H{"error": "workflow not found"})
+		} else {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to load workflow"})
+		}
+		return
+	}
+	if w.TeamID != nil {
+		c.JSON(http.StatusConflict, gin.H{"error": "workflow already belongs to a team"})
+		return
+	}
+
+	patch := models.WorkflowPatch{TeamID: &teamID}
+	if err := h.stores.Workflows.Update(c.Request.Context(), wfID, patch); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to adopt workflow"})
+		return
+	}
+
+	// Return the updated workflow
+	c.Set("id", wfID)
+	h.Get(c)
+}
+
+// ListGlobalWorkflows returns unowned workflows available for adoption.
+// GET /api/v1/teams/:teamId/workflows/available
+func (h *WorkflowHandler) ListGlobalWorkflows(c *gin.Context) {
+	result, err := h.stores.Workflows.ListGlobal(c.Request.Context())
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to list workflows"})
+		return
+	}
+	if result == nil {
+		result = []models.Workflow{}
+	}
+	c.JSON(http.StatusOK, gin.H{"data": result})
+}
+
 // ── Workflow CRUD ───────────────────────────
 
 // ListTeamWorkflows returns workflows owned by the team.