diff --git a/STACK.md b/STACK.md
index 1f2874c..ccfbe40 100644
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+++ b/STACK.md
@@ -12,27 +12,27 @@
 |-------|-----------|-----|
 | **Language** | Scala 3.3+ LTS | VirtusLab maintains the compiler. Scala 3 has cleaner syntax, given/using for DI, extension methods, enums, union types |
 | **Runtime** | JDK 21+ with Project Loom | Virtual threads = millions of lightweight threads, no async/callback hell |
-| **HTTP Server** | Tapir + JDK HttpServer | Tapir gives type-safe endpoint definitions with auto-generated OpenAPI docs. JDK HttpServer with `Executors.newVirtualThreadPerTaskExecutor()` is the lightest possible server |
+| **HTTP Server** | Tapir + Netty | Tapir gives type-safe endpoint definitions with auto-generated OpenAPI docs. Netty-based server for production use |
 | **Concurrency** | Ox | Structured concurrency, Go-like channels, error supervision, retries, rate limiting. Built on virtual threads |
 | **Database** | Magnum | Scala 3 native, typesafe SQL interpolator, auto-generated CRUD, no dependencies, works with any JDBC database |
-| **Migrations** | Flyway | Industry standard, JVM-native, works with any JDBC database |
+| **Migrations** | Liquibase | Supports rollbacks in free version (Flyway does not). Rollbacks are essential for dev workflow — drop last migration and fix, like in WinterCMS |
 
 ## Supporting Libraries
 
 | Concern | Library | Notes |
 |---------|---------|-------|
-| **JSON** | jsoniter-scala | Fastest JSON lib on JVM — author hand-tunes CPU instructions emitted by JVM. Only non-broken Scala JSON lib. May need a custom wrapper (~75% done) |
-| **Config** | [Jig](https://github.com/lbialy/jig) (HOCON) | Supports reading & writing including comments. Better discoverability for LLMs. Maintained by VL engineer with full control — we can add features as needed |
-| **Logging** | Scribe + Scribe SLF4J binding | Excellent performance, configured in code (no XML). SLF4J binding for Java lib compat. Avoid direct SLF4J — its config resolution rules are a nightmare |
+| **JSON** | jsoniter-scala | Fastest JSON lib on JVM. May need a custom wrapper (~75% done) |
+| **Config** | [Jig](https://github.com/lbialy/jig) (HOCON) | Supports reading & writing including comments. Better discoverability for LLMs. Maintained in-house — we can add features as needed |
+| **Logging** | Scribe + Scribe SLF4J binding | Excellent performance, configured in code (not XML). SLF4J binding for Java library compatibility |
 | **Caching** | Caffeine (in-memory) + Jedis/Lettuce (Redis) | Caffeine is the fastest JVM cache; Redis for distributed |
-| **Hashing** | jBCrypt + JDK crypto | Password hashing + general encryption. JDK is good enough; Bouncy Castle via JNI if performance-critical |
-| **Email** | Custom `summer-postcard` with driver trait | Jakarta Mail is legacy with Java failure modes (random NPEs). Emails are too critical for that. Need clean interface + multiple bindings: SMTP, AWS SES, etc. |
+| **Hashing** | jBCrypt + JDK crypto | Password hashing + general encryption. Bouncy Castle via JNI if performance-critical |
+| **Email** | `summer-postcard` with driver trait | Clean interface + multiple drivers: SMTP, AWS SES, etc. |
 | **HTTP Client** | sttp | Best HTTP client on JVM. Pairs with Tapir (same ecosystem). Handles sessions, cookies, streaming, HTTP auth |
 | **Admin Frontend** | Vue.js 3 + TypeScript | SPA admin panel consuming Tapir API |
-| **OpenAPI codegen** | Tapir -> OpenAPI -> openapi-typescript | Auto-generated TS types from Tapir endpoint definitions. VL has working template for this. Enables 1:1 API bindings + drift detection |
-| **Template Engine** | Pebble | Twig-like syntax (preserves WinterCMS familiarity). Scalate is abandonware — avoid. Needs investigation: file-based loading + hot-reload in dev (file watcher fallback if needed) |
-| **CLI** | case-app | By Alex Archambault (original scala-cli author). Auto-generated help, parsed case classes. Scopt has bad assumptions; Decline is too complex for LLMs to use effectively |
-| **Testing** | MUnit + testcontainers-scala + Tapir test utils | MUnit only — no ScalaTest (build issues, unreliable cross-platform publishing). testcontainers-scala for integration tests (Postgres etc.) |
+| **OpenAPI codegen** | Tapir -> OpenAPI -> openapi-typescript | Auto-generated TS types from Tapir endpoint definitions. Enables 1:1 API bindings + drift detection |
+| **Template Engine** | Pebble | Twig-like syntax (preserves WinterCMS familiarity). Needs investigation: file-based loading + hot-reload in dev |
+| **CLI** | case-app | Auto-generated help, parsed case classes, simple and LLM-friendly |
+| **Testing** | MUnit + testcontainers-scala + Tapir test utils | MUnit for unit tests, testcontainers-scala for integration tests (Postgres etc.) |
 | **Build (project)** | sbt | Multi-module build for the subprojects |
 | **Build (scripts)** | scala-cli | Quick scripts, prototyping, dev tooling. VirtusLab maintains it |
 
@@ -51,15 +51,16 @@ Each module = separate sbt subproject, publishable independently (like Illuminat
 | **Events** | `summer-festival` | Simple event bus with typed events + Ox channels for async |
 | **Http** | `summer-surf` | Tapir endpoint definitions + sttp client, request/response wrappers, routing (Tapir endpoints are type-safe routes) |
 | **Database** | `summer-lagoon` | Magnum repos + immutable case class models + query builder + pagination. **Key challenge:** Scala immutability vs Eloquent/Doctrine mutation patterns — use `copy()` + repo.save() for single entities. Relations are the hardest part to model (see open questions) |
-| **Auth** | `summer-bouncer` | JWT tokens (for API) + session cookies (for admin), guards as traits, session management. JWT needs separate investigation — no good Scala-native JWT lib yet, may use Spring's JWT implementation |
+| **Auth** | `summer-bouncer` | JWT tokens (for API) + session cookies (for admin), guards as traits, session management. JWT via proven Java JWT library |
 | **Validation** | `summer-lifeguard` | Compile-time via Scala types + runtime rules engine (inspired by fields.yaml) |
 | **Cache** | `summer-cooler` | Caffeine + Redis, driver-based via trait |
-| **Queue** | `summer-conga` | Ox channels + virtual threads for workers, persistent queue via DB or Redis |
-| **Mail** | `summer-postcard` | Clean email interface with driver trait + template support. Drivers: SMTP, AWS SES, etc. No Jakarta Mail dependency |
+| **Queue** | `summer-conga` | Persistent queue for offloading heavy work from the HTTP hot path. Driver-based: Postgres table, ActiveMQ, Redis, etc. Guarantees that enqueued jobs are not lost and are eventually executed. Virtual threads for workers |
+| **Mail** | `summer-postcard` | Clean email interface with driver trait + template support. Drivers: SMTP, AWS SES, etc. |
 | **Console** | `summer-bonfire` | CLI command framework via case-app for scaffolding (`summer create:plugin`, etc.) |
 | **Filesystem** | `summer-sandcastle` | `java.nio.file` + pluggable storage providers (S3, etc.) via driver trait |
 | **Translation** | `summer-phrasebook` | i18n with HOCON/JSON locale files |
 | **View** | `summer-sunset` | Template engine for admin panel rendering |
+| **Plugins** | `summer-party` | Plugin system: versioned plugin interfaces, resolution system, ServiceLoader-based runtime discovery. Private plugin registry with version compatibility extracted from published artifacts |
 
 ### Illuminate Packages Not Ported (and why)
 
@@ -68,20 +69,22 @@ Each module = separate sbt subproject, publishable independently (like Illuminat
 | **Pipeline** | Function composition is native to Scala (`f andThen g`). Laravel needs a Pipeline class because PHP lacks first-class functions. In Scala this is a one-liner, not a module. | Inline wherever needed |
 | **Routing** | Tapir endpoint definitions ARE routes — defining an endpoint and defining a route is the same thing. No separate routing layer needed. | Merged into `summer-surf` (http) |
 | **Session** | For an API-first CMS with JWT, sessions are thin — only needed for admin panel cookies. Not enough to justify a standalone module. | Merged into `summer-bouncer` (auth) |
-| **Log** | Scribe handles logging directly with code-based configuration. No XML config hell, no SLF4J resolution rules. SLF4J binding provided for Java library compatibility. No need for a separate module. | Direct Scribe usage |
+| **Log** | Scribe handles logging directly with code-based configuration. SLF4J binding provided for Java library compatibility. | Direct Scribe usage |
 | **Collections** | Scala stdlib collections are already excellent — `List`, `Map`, `Seq`, `Vector` with `map`, `filter`, `fold`, etc. No wrapper needed. | Scala stdlib |
-| **Pagination** | A paginator is a case class + a few helper methods. Too small for a standalone module. | Merged into `summer-lagoon` (database) |
+| **Pagination** | Two aspects: DB-level query pagination (in `summer-lagoon`) and template/API pagination helpers (in `summer-surf` / `summer-sunset`). Not enough for a standalone module. | Split across `summer-lagoon` + `summer-surf` |
 
 ---
 
 ## Plugin & Theme System
 
-### Plugins
+### Plugins (`summer-party`)
 
-Each plugin = a directory with a `Plugin.scala` descriptor (same lifecycle as WinterCMS).
+Plugins are published JVM artifacts (JARs), discovered at runtime via **ServiceLoader**.
 
-- Descriptor declares: models, controllers, components, console commands, event listeners, navigation items
-- Plugins discovered at boot via classpath scanning or manifest
+- `summer-party` defines versioned plugin interfaces — a common contract all plugins implement
+- Plugins discovered at boot via ServiceLoader (runtime-based, not classpath scanning)
+- Version compatibility: registry extracts interface versions from published artifacts to know which plugins work with which CMS version
+- Plugin descriptor declares: models, controllers, components, console commands, event listeners, navigation items
 - Plugins can extend other plugins' models via Scala 3 extension methods + event hooks
 - Plugin lifecycle: `register()` -> `boot()`
 
@@ -159,6 +162,7 @@ summercms/
     summer-sandcastle/         # Filesystem + storage providers
     summer-phrasebook/         # Translation / i18n
     summer-sunset/             # View / templates
+    summer-party/              # Plugin system + registry
   app/                         # Full CMS application (depends on all modules)
     summer-cms/                # Assembled CMS with admin panel
   plugins/                     # Example/core plugins
@@ -193,6 +197,7 @@ Single-entity CRUD via `copy()` + repo is straightforward. **Relations are the h
 ### Other open items
 
 - **Pebble hot-reload**: Can Pebble load templates from filesystem (not classpath) and hot-reload on change? If not, implement file watcher that reloads the template engine on file changes. See [Pebble docs](https://deepwiki.com/PebbleTemplates/pebble)
-- **JWT library**: No good Scala-native JWT solution. Evaluate Spring's JWT implementation or write a thin wrapper. sttp/Tapir handle HTTP auth but not JWT token generation/validation
+- **JWT library**: Evaluate proven Java JWT libraries for token generation/validation
 - **jsoniter-scala wrapper**: ~75% complete wrapper exists. Evaluate if it needs finishing or if raw jsoniter-scala is sufficient
-- **API drift detection**: VL has know-how for static verification that services connect correctly post-deployment (from Yaga/Besom project). Integrate into dev loop and CI
+- **API drift detection**: Static verification that services connect correctly post-deployment. Integrate into dev loop and CI
+- **Plugin registry**: Design private plugin registry — extract interface versions from published artifacts to determine CMS version compatibility