docs: add external documentation site content

Add structured documentation covering quickstart, architecture, core
concepts, API reference, adapter guides, CLI commands, deployment
options, and operator/developer guides.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/start/quickstart.md

@@ -0,0 +1,61 @@
+---
+title: Quickstart
+summary: Get Paperclip running in minutes
+---
+
+# Quickstart
+
+Get Paperclip running locally in under 5 minutes.
+
+## Option 1: Docker Compose (Recommended)
+
+The fastest way to start. No Node.js install needed.
+
+```sh
+docker compose -f docker-compose.quickstart.yml up --build
+```
+
+Open [http://localhost:3100](http://localhost:3100). That's it.
+
+The Docker image includes Claude Code CLI and Codex CLI pre-installed for local adapter runs. Pass API keys to enable them:
+
+```sh
+ANTHROPIC_API_KEY=sk-... OPENAI_API_KEY=sk-... \
+  docker compose -f docker-compose.quickstart.yml up --build
+```
+
+## Option 2: Local Development
+
+Prerequisites: Node.js 20+ and pnpm 9+.
+
+```sh
+pnpm install
+pnpm dev
+```
+
+This starts the API server and UI at [http://localhost:3100](http://localhost:3100).
+
+No Docker or external database required — Paperclip uses an embedded PostgreSQL instance by default.
+
+## Option 3: One-Command Bootstrap
+
+```sh
+pnpm paperclip run
+```
+
+This auto-onboards if config is missing, runs health checks with auto-repair, and starts the server.
+
+## What's Next
+
+Once Paperclip is running:
+
+1. Create your first company in the web UI
+2. Define a company goal
+3. Create a CEO agent and configure its adapter
+4. Build out the org chart with more agents
+5. Set budgets and assign initial tasks
+6. Hit go — agents start their heartbeats and the company runs
+
+<Card title="Core Concepts" href="/start/core-concepts">
+  Learn the key concepts behind Paperclip
+</Card>