[feat] pluggable extension system

[stooit]

Summary

Adds a pluggable extension system that lets downstream deployments inject pages, navigation items, and sidebar sections into Lagoon UI without modifying core code.

Extensions are defined as directories under extensions/, each with an extension.json manifest. At build time, build-extensions copies pages and components into the app and generates a merged extensions.json. At runtime, the ExtensionProvider reads this manifest and makes it available to navigation components.

Included change

• Build script (scripts/build-extensions.ts) discovers extensions, copies pages/components/lib into the app tree, writes merged manifest
• Manifest schema & validation (src/lib/extensions/schema.ts) validates extension.json at load time
• Runtime loader (src/lib/extensions/loader.ts) reads extensions.json and provides it via ExtensionContext
• Navigation integration sidebar (useSidenavItems), project tabs (ProjectNavTabs), environment tabs (EnvironmentNavTabs) all pick up extension nav items
• RBAC (src/lib/extensions/rbac.ts, ExtensionRouteGuard) role-based access on nav items and pages via requiredRoles/excludeRoles
• Icon mapping (src/lib/extensions/icons.ts) maps Lucide icon names from manifests to components

Extension structure

extensions/my-extension/
├── extension.json          # manifest
├── pages/                  # → copied to src/app/(routegroups)/
│   └── my-page/
│       └── page.tsx
├── components/             # → copied to src/components/extensions/<name>/
│   └── MyComponent.tsx
└── lib/                    # → copied to src/lib/extensions/<name>/
    └── utils.ts

Manifest format

{
  "meta": { "name": "my-extension", "version": "1.0.0" },
  "navigation": {
    "items": [
      {
        "id": "my-page",
        "label": "My Page",
        "href": "/my-page",
        "icon": "Star",
        "target": "sidebar-projects"
      }
    ],
    "sections": [
      {
        "section": "My Section",
        "position": "end",
        "items": [
          { "id": "item1", "label": "Item", "href": "/item", "icon": "Star" }
        ]
      }
    ]
  },
  "pages": [
    { "route": "my-page", "requiredRoles": ["admin"] }
  ]
}

Navigation targets

Target	Location
sidebar-projects	Projects section in sidebar
sidebar-deployments	Deployments section
sidebar-organizations	Organisations section
sidebar-settings	Settings section
project-tabs	Project page tabs
environment-tabs	Environment page tabs

Docker usage

Downstream images will need to optionally inject extensions before build:

COPY my-extensions/ /app/extensions/
RUN yarn build

Working example

A "functional" analytics dashboard example available here: feat/extensions-example:

• extensions/analytics/extension.json - manifest with sidebar section, project tab, RBAC rules
• extensions/analytics/pages/analytics/page.tsx - global dashboard with charts
• extensions/analytics/pages/projects/[projectSlug]/analytics/page.tsx project-level analytics page
• extensions/analytics/components/ StatCard, ChartCard components