BOSA Sidebar Integration for BP_WB

Add sidebar link support for apps in apps/ directory. BP_WB needs a "Theme Builder" link for Super Admin only, positioned after "Themes".

Requirements:
1. Read sidebar config from apps/*/manifest.yaml (sidebar section) or apps/*/sidebar.json
2. Filter by role (super_admin only)
3. Support positioning: position: "after" with after: "themes"
4. Merge app links with core sidebar links

Config format (apps/bp_wb/manifest.yaml):
  sidebar:
    label: Theme Builder
    url: /bp_wb/
    icon: pencil-square
    role: super_admin
    position: after
    after: themes

Result: Super Admin sees "Theme Builder" link after "Themes" → /bp_wb/