docs(architecture): rewrite overview for vertical feature architecture

docs/architecture/overview.md

@@ -1,55 +1,58 @@
 # Architecture Overview
 
-## Clean Architecture Monorepo
+A vertical-feature monorepo. Business capabilities are top-level packages; non-business foundations are `core-*`.
 
-This template implements Uncle Bob's Clean Architecture in a Turborepo + pnpm monorepo. The core principle: **dependencies point inward only**.
+## Package map
 
 ```
-┌─────────────────────────────────────────────────┐
-│  Frameworks & Drivers (outermost)               │
-│  Next.js, TanStack Start, Payload CMS,          │
-│  Storybook, PostgreSQL, Docker                  │
-│  ┌─────────────────────────────────────────┐    │
-│  │  Interface Adapters                     │    │
-│  │  tRPC routers, Controllers, Presenters  │    │
-│  │  ┌─────────────────────────────────┐    │    │
-│  │  │  Application (Use Cases)        │    │    │
-│  │  │  Business logic, interfaces     │    │    │
-│  │  │  ┌─────────────────────────┐    │    │    │
-│  │  │  │  Entities (innermost)   │    │    │    │
-│  │  │  │  Models, Errors, Zod    │    │    │    │
-│  │  │  └─────────────────────────┘    │    │    │
-│  │  └─────────────────────────────────┘    │    │
-│  └─────────────────────────────────────────┘    │
-└─────────────────────────────────────────────────┘
+packages/
+  # Foundation (no business logic)
+  core-shared/    Generic primitives — Payload field/block helpers, tRPC init/context, lib utilities
+  core-cms/       Composition only: assembles feature CMS exports into one Payload config
+  core-api/       Composition only: aggregates feature tRPC routers into one appRouter
+  core-trpc/      Frontend tRPC client + per-framework providers (Next.js, TanStack)
+  core-ui/        Design-system primitives (atoms, molecules, generic organisms, templates)
+
+  # Business capabilities
+  auth/             Users + sign-in/sign-up/sign-out + session/cookie domain
+  blog/             Articles collection + publishing flow
+  media/            Media upload collection (skeleton; expand with optimization, CDN, etc.)
+  marketing-pages/  Pages collection + SiteSettings global
+  navigation/       Header global + menu items
+
+  # Tooling
+  eslint-config/    Shared ESLint flat config + boundary rules
+  typescript-config/ Shared tsconfig + vitest base
 ```
 
-## Package Map
+## Data flow
 
 ```
-packages/core         → Clean architecture (entities, use cases, infra, DI)
-packages/api          → tRPC routers (calls core controllers)
-packages/api-client   → Shared React Query hooks + provider
-packages/cms-core     → Payload CMS config, collections, hooks
-packages/cms-client   → Dual-mode Payload client (local + HTTP)
-packages/ui           → Atomic Design + shadcn/ui + Tailwind v4
-
-apps/web-next         → Next.js 15 reference app
-apps/web-tanstack     → TanStack Start reference app
-apps/cms              → Thin Next.js shell for Payload admin
-apps/storybook        → Centralized Storybook instance
+React component
+  ↓ useQuery(trpc.blog.articleBySlug.queryOptions(...))   ← ui/query.ts (typed tRPC client)
+HTTP /api/trpc
+  ↓
+tRPC procedure                     ← integrations/api/router.ts
+  ↓ .input(zod).query(...)
+Controller (Zod safeParse)         ← interface-adapters/controllers/
+  ↓
+Use case                           ← application/use-cases/
+  ↓ container.get(SYMBOL)
+Repository implementation          ← infrastructure/repositories/ (@injectable)
+  ↓ getPayload({ config })
+Payload Local API → Postgres
 ```
 
-## Data Flow
+## Three enforcement layers
 
-```
-UI → useQuery(trpc.content.list) → tRPC Router → Controller → Use Case → Repository → Payload Local API → PostgreSQL
-```
+1. **`package.json` deps** — only declare allowed deps
+2. **`exports` map** — each package exposes a small public surface (`.`, `./cms`, `./api`, `./di/bind-production`)
+3. **ESLint `eslint-plugin-boundaries`** — three tags (`app`, `feature`, `core`); two composition exceptions (`core-api` may import `@repo/<feature>/api`; `core-cms` may import `@repo/<feature>/cms`)
 
-## Key Design Decisions
+## Per-feature DI containers
 
-- **InversifyJS DI** — symbol-based resolution, documented in di/AGENTS.md
-- **Dual-mode CMS client** — Local API for server-side (no HTTP overhead), HTTP for external
-- **Atomic Design** — atoms/molecules/organisms/templates, co-located stories
-- **tRPC single data path** — all data (including CMS content) flows through tRPC
-- **Agent-optimized docs** — AGENTS.md at every level with rules, recipes, tables
+Each feature owns its own InversifyJS `Container` + symbol table. No shared symbols, no cross-feature DI coupling. Tests rebind per feature without touching others. Apps call `bindProduction*(config)` per feature at boot to swap the default mock implementations for Payload-backed ones.
+
+## Spec reference
+
+`docs/architecture/vertical-feature-spec.md` is the canonical design.