✨ feat: add admin-ui-config, content-authoring, and frontend-architecture skills documentation

- Introduced `admin-ui-config` skill for configuring admin UI for collections.
- Added `content-authoring` skill detailing page and block creation in the CMS.
- Included `frontend-architecture` skill explaining custom SPA routing and state management.
- Updated `AGENTS.md` to reference new skills and provide infrastructure prerequisites.
- Enhanced `frontend/AGENTS.md` with routing details and SPA navigation information.

AGENTS.md

@@ -59,6 +59,27 @@ Tibi CMS starter template — Svelte 5 SPA with esbuild, SSR via goja, and Playw
 - API access to collections uses the reverse proxy: `CODING_URL/api/<collection>` (e.g. `CODING_URL/api/content`).
 - Auth via `Token` header with ADMIN_TOKEN from `api/config.yml.env`.
 
+## Required secrets and credentials
+
+| Secret | Location | Purpose |
+| --- | --- | --- |
+| `ADMIN_TOKEN` | `api/config.yml.env` | API admin auth + tibi-admin login |
+| `SENTRY_AUTH_TOKEN` | Gitea repo secrets | Sourcemap upload to Sentry (CI only) |
+| `.basic-auth-web` | project root (git-ignored) | Basic auth for BrowserSync dev server |
+| `.basic-auth-code` | project root (git-ignored) | Basic auth for Code-Server / admin |
+| `RSYNC_PASS` | Gitea secrets (`github.token`) | rsync deployment password (CI only) |
+
+**Note:** `.basic-auth-web` and `.basic-auth-code` are plain text files in `user:password` format (htpasswd). They are required by Docker Traefik labels for dev environment access. Curl and Playwright requests are let through without basic auth via Traefik label configuration.
+
+## Infrastructure prerequisites
+
+- **Code-Server environment** — This project is designed for development on a Code-Server instance at `*.code.testversion.online` with a **Traefik reverse proxy** managing HTTPS and auto-routing via Docker labels.
+- **Without Code-Server/Traefik** — The Docker stack starts but the website is not reachable via hostname. Workaround: access BrowserSync directly via `http://localhost:3000` (requires exposing the port in `docker-compose-local.yml`).
+- **Docker + Docker Compose** — Required for all development. Never run `yarn dev` or `yarn start` locally.
+- **MongoDB** — Runs as a Docker service (`mongo`). Data persists in `tmp/mongo-data/`.
+- **Production** — Deployed via rsync to an existing server running tibi-server + MongoDB. The frontend is a static SPA served by a Node.js webserver (`webserver/webserver.js`) or directly by tibi-server.
+- **Staging** — Docker Compose builds a `www` container that connects to an external tibi-server at `dev-tibi-server.staging.testversion.online`.
+
 ## Reference repositories
 
 These sibling repos in the workspace provide documentation, types, and reference implementations:
@@ -100,6 +121,19 @@ Project-specific types (e.g. `Ssr`, `ApiOptions`, `ContentEntry`) live in `types
 - **Zero warnings policy**: After making changes, always run `yarn validate` and check the IDE problems tab. Fix all TypeScript, Svelte, and Tailwind warnings — the codebase must stay warning-free.
 - When Tailwind `suggestCanonicalClasses` warnings appear, always fix the **source** `.svelte`/`.ts`/`.css` file — never the compiled output.
 
+### Architecture skills (loaded on demand)
+
+These skills provide deep-dive documentation. Use them when working on the respective area:
+
+| Skill | When to use |
+| --- | --- |
+| `content-authoring` | Adding new pages, content blocks, or collections |
+| `frontend-architecture` | Routing, state management, Svelte 5 patterns, API layer, error handling |
+| `admin-ui-config` | Configuring collection admin views, field widgets, layouts |
+| `tibi-hook-authoring` | Writing or debugging server-side hooks |
+| `tibi-ssr-caching` | SSR rendering and cache invalidation |
+| `tibi-project-setup` | Setting up a new project from scratch |
+
 ### Tailwind CSS 4 canonical classes
 
 This project uses Tailwind CSS 4. Always use the canonical v4 syntax: