[4.3] Integrate Toast Component

[adnaan]

Description

Add toast notifications to generated apps using the toast component. This provides standardized user feedback.

Depends on: #4.1

Tasks

• Add toast.ContainerState to generated handler state
• Add toast container to layout template
• Add success toasts after create/update/delete actions
• Add error toasts on failures
• Register toast templates in main.go

Acceptance Criteria

• Generated apps show toast on CRUD operations
• Toasts auto-dismiss after timeout
• Toast position is configurable

Files to Modify

• internal/generator/templates/resource/handler.go.tmpl
• internal/kits/system/*/templates/components/layout.tmpl

[adnaan]

Completed in PR #142 — toast container integrated with CRUD success feedback (Add, Update, Delete).