Auth docs.

docs/AUTH_SETUP.md

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+# Authentication Setup
+
+SSO for homelab services using OIDC.
+
+## Architecture
+
+**Pocket ID** (`pocket-id.v.paler.net`) - Lightweight OIDC provider, data in `/data/services/pocket-id`
+
+**Traefik** - Uses `traefik-oidc-auth` plugin (v0.16.0) to protect services
+- Plugin downloaded from GitHub at startup, cached in `/data/services/traefik/plugins-storage`
+- Middleware config in `/data/services/traefik/rules/middlewares.yml`
+- Protected services add tag: `traefik.http.routers.<name>.middlewares=oidc-auth@file`
+
+## Flow
+
+1. User hits protected service → Traefik intercepts
+2. Redirects to Pocket ID for login
+3. Pocket ID returns OIDC token
+4. Traefik validates and forwards with `X-Oidc-Username` header
+
+## Protected Services
+
+Use `oidc-auth@file` middleware (grep codebase for full list):
+- Wikis (TiddlyWiki instances)
+- Media stack (Radarr, Sonarr, Plex, etc.)
+- Infrastructure (Traefik dashboard, Loki, Jupyter, Unifi)
+
+## Key Files
+
+- `services/pocket-id.hcl` - OIDC provider
+- `services/traefik.hcl` - Plugin declaration
+- `/data/services/traefik/rules/middlewares.yml` - Middleware definitions (oidc-auth, simple-auth fallback)
+
+## Cold Start Notes
+
+- Traefik needs internet to download plugin on first start
+- Pocket ID needs `/data/services` NFS mounted
+- Pocket ID down = all protected services inaccessible
+
+## Troubleshooting
+
+**Infinite redirects**: Check `TRUST_PROXY=true` on Pocket ID
+
+**Plugin not loading**: Clear cache in `/data/services/traefik/plugins-storage/`, restart Traefik
+
+**401 after login**: Verify client ID/secret in middlewares.yml matches Pocket ID client config
+
+## Migration History
+
+- Previous: Authentik with forwardAuth (removed Nov 2024)
+- Current: Pocket ID + traefik-oidc-auth (simpler, lighter)
+
+---
+
+*Manage users/clients via Pocket ID UI. Basic auth fallback available via `simple-auth` middleware.*