Initial commit: SummerCMS Go planning docs and research

Records the move from Scala to Go, the compiled-plugin decision, the
Płytarium port as the v1 target, and the Go ecosystem research that
backs the choice. No code yet.

.planning/notes/v1-target-plytarium.md

@@ -0,0 +1,73 @@
+---
+title: v1 target — Płytarium port
+date: 2026-09-16
+context: Chosen during the opening exploration session over the smaller `inventory` project. Defines v1 scope and the acceptance rule.
+---
+
+# v1 target: Płytarium port
+
+**Definition of done for v1:** `vue-fonoteka-app` (Nuxt 4) runs unchanged against the SummerCMS Go backend, and `fonoteka-mcp` talks to it through the same OAuth2 flow it uses today.
+
+Płytarium is the `fonoteka` project at `/media/nvme/dev/golem15/fonoteka`. It is a headless WinterCMS backend for a household record collection, forked from `wn-inventory-plugin`, on the Golem15 starter v1.1.8 LTS.
+
+## Why this one
+
+- Headless. No theme engine needed in v1.
+- Actively developed and actually used, so "done" is testable by daily use.
+- It forces every ecosystem claim at once: OAuth2/OIDC provider, background jobs, realtime, search, file uploads, external APIs, org-scoped permissions.
+- Roughly three times the size of `inventory`, which was the alternative. Large enough to be real, small enough to finish.
+
+## What must be ported
+
+### Domain plugin `golem15.fonoteka`
+
+| Aspect | Count |
+|---|---|
+| Models | 25 (Album, Artist, Collection, Genre, Style, AlbumRating, AlbumReservation, ApiToken, CollectionEditor, CollectionInvitation, CsvImport, CsvImportRow, Notification, OAuthAuthCode, OAuthClient, OAuthRefreshToken, OrgAiCredential, OrgDiscogsCredential, PendingInvitationRegistration, Settings, UserAiCredential, UserCollectionContext, UserDiscogsCredential, WishlistDigestQueue, WishlistSubscription) |
+| Admin controllers | 5 (Albums, Artists, Collections, Genres, Styles) with YAML-driven forms and lists |
+| API routes | 160 (collections, albums, wishlist, sharing, notifications, realtime channels, CSV export, locale, context) |
+| Migrations | 27 |
+| Console commands | 3 (IssueOAuthClient, PruneNotifications, ReindexAlbums) |
+| Jobs | CSV import, wishlist digest |
+| Test files | 143 |
+| PHP lines | ~57k |
+
+### Stack plugins in play
+
+| Plugin | Role in Płytarium |
+|---|---|
+| user | Accounts, JWT, organizations, the base of the OAuth2 provider |
+| backend | Admin panel improvements |
+| apparatus | DI, scenarios, backend tooling |
+| golem | AI integration (cover recognition via Anthropic / OpenAI) |
+| translate | pl / en |
+| websockets | Realtime via Centrifugo |
+| userfriends | Friends and groups for collection sharing (optional) |
+| journal | Blog / notes (optional) |
+| feedback | Feedback submissions |
+| sitemap | Sitemap |
+
+### Hard parts, and the Go answer from research
+
+| Hard part | Go pick |
+|---|---|
+| OAuth2 provider used by ChatGPT connector and MCP | `zitadel/oidc` |
+| JWT for the SPA | `golang-jwt/jwt` |
+| Queued jobs (CSV import, digests) | `riverqueue/river` (Postgres-backed) |
+| Realtime notifications | `coder/websocket`, or keep Centrifugo and port only the publisher |
+| Search (Typesense via Scout today) | Typesense Go client |
+| File uploads, cover images | `gocloud.dev/blob` |
+| Discogs, Anthropic, OpenAI HTTP clients | stdlib `net/http`, official Anthropic Go SDK |
+| Validation of YAML `rules:` | `go-playground/validator` |
+
+## Out of scope for v1
+
+- Server-rendered themes and components. Second target: keios.eu (see `../seeds/keios-port-themes-payments.md`).
+- Payments (paymentgateway, pgstripe). Same second target.
+- Chat, forum, video. wavepath.org territory, later.
+- WASM extension API. See `../seeds/wasm-extension-api.md`.
+
+## Reference material
+
+- `wavepath.org/plugins/golem15/oauthserver` (11k lines, has tests and `INTEGRATING.md`) is the fuller OAuth2 implementation in the stack. Use it as the behavioral reference for the user plugin's OIDC port even though Płytarium's own OAuth models are smaller.
+- `fonoteka/.planning/` holds the GSD history of the PHP project, including `STARTER-LINEAGE.md`.