docs: slim README, move detail into per-app and contributor docs

README down to the Containr skeleton: header, three-screenshot row
(rest behind <details>), features, architecture, quick start, links.
Dropped tables and sections already covered by QUICK_START.md.
Native dev commands and repo layout moved to CONTRIBUTING.md;
CLI/MCP usage moved to new per-app READMEs.

Authored By: TDvorak <[email protected]>

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

CONTRIBUTING.md

@@ -9,9 +9,24 @@ cp .env.example .env
 docker compose up -d --build
 ```
 
-For native development run only the infrastructure in Docker
-(`docker compose up -d postgres dragonfly mailpit`) and start the three
-services yourself.
+For native development run only the infrastructure in Docker and start the
+three services yourself:
+
+```bash
+docker compose up -d postgres dragonfly mailpit   # infrastructure only
+cd apps/backend && go run ./cmd/server            # API on :8080
+npm run dev:auth                                  # auth on :3001
+npm run dev:frontend                              # dashboard (Vite)
+```
+
+Point the frontend at the stack via `apps/frontend/.env.local`:
+
+```env
+VITE_API_BASE_URL=http://localhost/api/v1
+VITE_AUTH_BASE_URL=http://localhost/auth
+```
+
+Or skip the backend entirely: `?demo=true` runs a fully client-side workspace.
 
 ## Workflow
 
@@ -29,6 +44,23 @@ services yourself.
    If you changed `apps/backend/openapi/openapi.yaml`, run
    `npm run generate:client`. Commit the regenerated output with your change.
 
+## Repository layout
+
+```
+apps/
+  backend/     Go + Gin API, sqlc, migrations, object storage
+  auth/        Better Auth on Hono (sessions, JWT, OAuth, mail)
+  frontend/    SolidJS + Tailwind dashboard
+  cli/         `primora` CLI - login, context, projects, buckets, objects, keys, audit
+  mcp/         `@primora/mcp` - MCP stdio server exposing `primora_*` tools
+  desktop/     Tauri 2 shell - connects to a deployment URL, tray presence
+packages/
+  api-client/  OpenAPI-generated TypeScript client (do not hand-edit)
+  shared-types/
+infra/nginx/   Reverse proxy config
+scripts/       setup.sh, verify-production-ready.sh
+```
+
 ## Conventions
 
 - **Generated code is never hand-edited** — `packages/api-client/src/generated`