linearvoid/docs/SETUP.md

# Linear Void Setup Guide

**Last Updated**: 2026-08-03

This guide covers prerequisites, environment setup, running the application locally and in production, and troubleshooting. It references the [architecture documentation](./docs/architecture/README.md)(`docs/architecture/README.md`).

## Prerequisites

- **Docker & Docker Compose**: Required for running the full stack (playout, chat, nginx, redis, db, prometheus, grafana). Install from [docker.com](https://www.docker.com).
- **Node.js 22+**: Required for frontend development and production builds (`cd frontend && npm install && npm run build`).
- **npm**: Installed with Node.js and used for the frontend dependency installation and Vite workflow.
- **Go 1.25+**: Recommended when working on the Go services outside Docker (`backend/chat`, `backend/playout`).
- **FFmpeg**: Used by the playout service for HLS generation. Install via `apt install ffmpeg` (Linux), Homebrew (macOS), or Winget (Windows).
- **Git**: For cloning and version control.
- **Cloudflare Account**: For R2 storage and CDN (free tier sufficient for most use cases).
- **Gitea Account**: Required if you want to push images to the self-hosted registry or use the repository's CI/CD flow.
  - Set up the required Actions secrets in Gitea at: [https://git.allucanget.biz/zwitschi/linearvoid/settings/actions/secrets](https://git.allucanget.biz/zwitschi/linearvoid/settings/actions/secrets)
  - Add the following secrets:
    - `CI_REGISTRY_USER`: Your Gitea username (e.g., `zwitschi`)
    - `CI_REGISTRY_TOKEN`: A Gitea Personal Access Token with `write:packages` scope
    - `ADMIN_USERNAME`: The administrator username for the production admin panel (e.g., `admin`)
    - `ADMIN_PASSWORD`: A strong password for the production admin panel
    - `DATABASE_URL`: The production database connection string (e.g., `postgres://linearvoid:<password>@db:5432/linearvoid?sslmode=disable`)
- **Hetzner Cloud Account** (optional for production): For the US-East VPS (Ashburn, VA recommended per ADR-001).

## Network Environments

Linear Void operates in two distinct environments. Know which one you're targeting.

```mermaid
flowchart LR
    subgraph Test_Lab["Test Lab (192.168.88.0/24)"]
        TEST_HOST["192.168.88.40<br/>Docker Engine :2375"]
    end

    subgraph Prod["Production (Hetzner — NOT provisioned)"]
        PROD_HOST["Hetzner CX22 Ashburn, VA<br/>Public IP TBD"]
    end

    subgraph Gitea["Gitea CI/CD"]
        CI["CI: build + push images"]
        CD["CD: deploy via DOCKER_HOST"]
    end

    subgraph CF["Cloudflare"]
        DNS["linearvoid.tv"]
        R2["R2 Bucket"]
    end

    CD -->|"DOCKER_HOST=tcp://192.168.88.40:2375"| TEST_HOST
    CD -.->|"DOCKER_HOST=tcp://&lt;hetzner-ip&gt;:2375<br/>(when provisioned)"| PROD_HOST
    TEST_HOST -->|"test traffic"| DNS
    PROD_HOST -.->|"production traffic"| DNS
    TEST_HOST --> R2
    PROD_HOST -.-> R2
```

**Test Lab (active):** Internal network `192.168.88.0/24`, host `192.168.88.40`. Receives automated CD deploys from Gitea Actions. Used for integration testing and staging validation.

**Production (pending):** Hetzner Cloud VPS, Ashburn VA. Not yet provisioned. CD workflow and compose files are ready — only `DOCKER_HOST` needs changing. See Production Deployment section in [DEPLOYMENT.md](./DEPLOYMENT.md) for cutover plan.

## Development Prerequisites

- **Frontend dependencies**: Run `cd frontend && npm install` before `npm run dev` or `npm run build`.
- **Docker build support**: Local development expects Docker to be able to build the `chat`, `playout`, and `nginx` images referenced in `docker-compose.yml`.
- **Data directories**: Create `data/playlist`, `data/media`, `data/hls`, and `data/chat` before the first run so bind mounts resolve cleanly.
- **Database choice**: The stack defaults to PostgreSQL in `docker-compose.yml`. If you want SQLite for local-only development, update `DATABASE_URL` in `.env` accordingly.
- **Redis availability**: Chat presence, rate limiting, and pub/sub require Redis. The compose stack provides it automatically.
- **Video inputs**: Source videos should be normalized before playout. If the playlist contains invalid files, the playout container will fail its validation flow.

## Environment Setup

1. **Clone the Repository** (if not already done):

   ```bash
   git clone https://git.allucanget.biz/zwitschi/linearvoid.git
   cd linearvoid
   ```

2. **Copy Environment File**:

   ```bash
   cp .env.example .env
   ```

3. **Configure `.env`** (copy from `.env.example` and replace placeholders)

4. **Check local value overrides for Docker Compose**:
   - `docker-compose.yml` builds images locally and maps the frontend build output from `frontend/dist` into nginx.
   - `docker-compose.prod.yml` pulls prebuilt images from the Gitea registry.
   - Internal container-to-container URLs should use compose hostnames, for example `REDIS_URL=redis://redis:6379/0` and `DATABASE_URL=postgres://linearvoid:<password>@db:5432/linearvoid?sslmode=disable`.
   - For production public routing, set `VITE_PUBLIC_APP_URL=https://linearvoid.tv`, `VITE_PUBLIC_WS_URL=wss://linearvoid.tv/ws`, and `VITE_PUBLIC_HLS_URL=https://media.linearvoid.tv/hls/playlist.m3u8`.

5. **Create Data Directories**:

   ```bash
   mkdir -p data/playlist data/media data/hls data/chat
   ```

6. **Prepare Sample Videos** (optional):
   - Place normalized MP4 files in `data/media/`.
   - Create a `data/playlist/playlist.txt` with paths (see ADR-001 for normalization requirements).

## Gitea Setup

1. **Create or verify a Gitea user**:
   - The user should have access to the repository and permission to read from the container registry.

2. **Create an access token**:
   - Generate a token with the scopes needed for package/registry access and, if applicable, repository automation.
   - Store it as `CI_REGISTRY_TOKEN` in `.env`.

3. **Configure Gitea Actions Secrets**:
   - Go to the repository settings page: [https://git.allucanget.biz/zwitschi/linearvoid/settings/actions/secrets](https://git.allucanget.biz/zwitschi/linearvoid/settings/actions/secrets)
   - Add the following secrets to enable automated CI/CD and production deployment:
     - `CI_REGISTRY_USER`: Your Gitea username (e.g., `zwitschi`).
     - `CI_REGISTRY_TOKEN`: Your Gitea Personal Access Token with `write:packages` scope.
     - `ADMIN_USERNAME`: The administrator username for the production admin panel (e.g., `admin`).
     - `ADMIN_PASSWORD`: A strong password for the production admin panel.
     - `DATABASE_URL`: The production database connection string (e.g., `postgres://linearvoid:<password>@db:5432/linearvoid?sslmode=disable`).

4. **Configure registry variables**:
   - Set `CI_REGISTRY_URL` to the Gitea host.
   - Set `CI_REGISTRY_NAMESPACE` to the image namespace, for example `zwitschi/linearvoid`.
   - Set `CI_REGISTRY_USER` to the account that will push or pull images.

5. **Authenticate Docker to the registry**:

   ```bash
   docker login git.allucanget.biz
   ```

6. **Build and publish images when needed**:
   - Local development uses `docker-compose.yml`, which builds from source.
   - Production uses `docker-compose.prod.yml`, which expects the `playout`, `chat`, and `nginx` images to exist in the configured Gitea registry namespace.

7. **Validate image availability**:
   - Before a production rollout, verify that the expected `:latest` tags can be pulled from the registry on the target server.

## Cloudflare R2 Setup

1. **Create an R2 bucket**:
   - Create a bucket such as `linearvoid-media` in Cloudflare R2.
   - Keep the bucket name aligned with `R2_BUCKET_NAME` in `.env`.

2. **Generate R2 API credentials**:
   - Create an access key pair with read/write permissions for the bucket.
   - Set `R2_ACCESS_KEY_ID`, `R2_SECRET_ACCESS_KEY`, and `R2_REGION=auto` in `.env`.

3. **Find the S3 endpoint**:
   - Use the account-scoped endpoint format `https://<account-id>.r2.cloudflarestorage.com`.
   - Store the account ID in both `R2_ENDPOINT` and `CLOUDFLARE_ACCOUNT_ID` where applicable.

4. **Bind a custom media domain**:
   - Attach a domain such as `media.linearvoid.tv` to the bucket.
   - Set `MEDIA_DOMAIN` to that hostname.

5. **Configure app-domain DNS and TLS**:
   - Point `linearvoid.tv` to the public entrypoint serving nginx.
   - Point `www.linearvoid.tv` to the same target and redirect it to `https://linearvoid.tv`.
   - Keep `media.linearvoid.tv` on the R2 custom domain path so HLS delivery stays split from the app origin.
   - Use Cloudflare proxied DNS with Full (strict) TLS so browser traffic uses `https://linearvoid.tv`, `wss://linearvoid.tv/ws`, and `https://media.linearvoid.tv`.

6. **Apply cache behavior**:
   - Configure the `.m4s` and `.m3u8` cache rules from [cache-rules](../docs/infrastructure/cloudflare/cache-rules.md).
   - Enable Smart Tiered Cache for the R2-backed hostname.
   - If you need header normalization for immutable segment caching, deploy `infrastructure/cloudflare/worker.js` to the same zone.

7. **Configure R2 CORS**:
   - Add CORS rules to allow the app domain to access the R2 bucket for HLS delivery.
   - Example CORS configuration:

   ```json
   [
     {
       "AllowedOrigins": ["https://linearvoid.tv"],
       "AllowedMethods": ["GET"],
       "AllowedHeaders": ["*"],
       "ExposeHeaders": ["ETag", "Cache-Control"],
       "MaxAgeSeconds": 3600
     }
   ]
   ```

8. **Verify access**:
   - Confirm uploads with an S3-compatible client such as `aws s3 ls --endpoint-url <R2_ENDPOINT>`.
   - After deployment, check Cloudflare analytics for cache hit ratio and origin request volume.

## Cloudflare

Use this section for full edge setup (DNS, Workers, cache, security, and monitoring).

Execution tracker: `docs/operations/cloudflare-uptimerobot-checklist.md`.

### 1. DNS Setup

1. Add apex record for `linearvoid.tv` pointing to the Cloudflare Worker.
2. Add `www` CNAME to the Cloudflare Worker and configure redirect to `https://linearvoid.tv`.
3. Add `media.linearvoid.tv` for split-domain HLS delivery.
4. Keep all records proxied (orange cloud) unless troubleshooting requires DNS-only mode.

### 2. R2 Bucket

1. Create bucket `linearvoid-media`.
2. Set location hint to `enam` (US-East).
3. Attach custom domain `media.linearvoid.tv` to the bucket.
4. Configure CORS rules to allow `https://linearvoid.tv` for HLS delivery.
5. Verify object read works from the custom domain.

### 3. Cache Rules

Configure Cloudflare Cache Rules:

1. HLS segment files (`*.ts`, `*.m4s`):
   - Cache: eligible
   - Edge TTL: `31536000`
   - Browser TTL: long-lived
   - Cache key: include full path
2. HLS manifests (`*.m3u8`):
   - Cache: eligible
   - Edge TTL: `2s`
   - Revalidation: enabled
3. Static assets (`*.js`, `*.css`):
   - Cache: eligible
   - Edge TTL: `1y`
   - Browser TTL: long-lived
   - Cache key: include full path
4. Validate behavior using response headers:
   - `Cf-Cache-Status` should move from `MISS` to `HIT` for hot objects

Reference: [cache-rules](../docs/infrastructure/cloudflare/cache-rules.md).

### 4. Cloudflare Workers

Also see [the automated Gitea Actions deployment guide](./operations/gitea-cloudflare-workers.md).

Manual setup:

1. Create a Cloudflare Worker for the static SPA (Workers & Pages → Create → Worker).
2. Build the frontend:

   ```bash
   cd frontend && npm run build
   ```

3. Bind the build output (`frontend/dist`) as Worker static assets.
4. Configure production domain `linearvoid.tv` on the Worker.

### 5. Tiered Cache

1. Enable Smart Tiered Cache in Cloudflare dashboard.
2. Warm a segment and manifest path.
3. Confirm tiered behavior through repeated requests and `Cf-Cache-Status: HIT`.

### 6. WAF and Bot Protection

1. Enable OWASP Managed Ruleset.
2. Start in `Simulate` mode.
3. Review events for 48 hours.
4. Switch to `Block` once false positives are addressed.
5. Enable Bot Fight Mode.

### 7. Rate Limiting

Create rules:

1. Path: `/api/admin/login`
2. Path: `/api/admin/*`
3. Threshold: `10 requests / 10 seconds / IP`
4. Action: `Managed Challenge`

### 8. HTTPS and WSS

1. Enable `Always Use HTTPS`.
2. Enable HSTS with:
   - `max-age=31536000`
   - `includeSubDomains`
   - `preload`
3. Minimum TLS version: `1.2`.
4. Keep SSL mode at `Full (strict)` when origin certs are valid.
5. Enforce HTTPS redirect at both layers:
   - Cloudflare edge
   - nginx origin
6. Validate websocket endpoint uses `wss://linearvoid.tv/ws`.

### 9. UptimeRobot Monitors

Create external monitors:

1. HTTP monitor:
   - URL: `https://linearvoid.tv/health`
   - Interval: 5 minutes
2. Keyword monitor:
   - URL: `https://linearvoid.tv/hls/playlist.m3u8`
   - Keyword: `#EXTM3U`
   - Interval: 5 minutes
3. Alert policy:
   - Trigger on 2 consecutive failures
   - Notify via email and Discord/Slack webhook

### 10. Verification Checklist

1. DNS resolves for `linearvoid.tv`, `www.linearvoid.tv`, and `media.linearvoid.tv`.
2. Workers serve frontend for apex and `www` redirects correctly.
3. HLS segments are cacheable long-term, manifests refresh every ~2s.
4. Admin paths are rate-limited and WAF events are visible.
5. HTTPS and WSS both succeed with valid certificates.
6. UptimeRobot alerts fire as expected when endpoints are intentionally made unavailable.

## Running the Application

### Local Development

1. **Start All Services**:

   ```bash
   docker compose up --build
   ```

2. **Access the Application**:
   - Preferred local access with the documented proxy setup: <https://linearvoid.tv>
   - Admin Interface: <https://linearvoid.tv/admin> (redirects to `/admin/login/` until authenticated)
   - Chat WebSocket: `wss://linearvoid.tv/ws`
   - Direct-local fallback when bypassing Cloudflare/Nginx Proxy Manager: <http://localhost>, <http://localhost/admin>, and `ws://localhost/ws`
   - Health Checks:
     - Playout: <http://localhost:8081/health>
     - Chat: <http://localhost:3000/health>
   - Monitoring:
     - Prometheus: <http://localhost:9090>
     - Grafana: <http://localhost:3001> (default login: admin/admin)

3. **Frontend Development** (optional, for UI changes):

   ```bash
   cd frontend
   npm install
   npm run dev
   ```

   The dev server runs on <http://localhost:5173>. It proxies API calls to the backend services.

4. **Build frontend assets for nginx-backed local runs**:

   ```bash
   cd frontend
   npm install
   npm run build
   ```

   The local nginx container serves `frontend/dist`, so rebuilding the frontend is required before validating production-like static output.

5. **Stop Services**:

   ```bash
   docker compose down
   ```

### Local Test Environment Deployment (Remote Docker Host)

For testing deployments on a local network server without setting up a full production VPS, you can deploy directly to a remote Docker host (e.g., a home lab server or test machine) using Docker's TCP socket.

#### Test Environment Prerequisites

- A remote server running Docker at IP `192.168.88.40` (running Alpine Linux).
- Docker TCP socket enabled and listening on port `2375` on the remote server.

##### Enabling Docker TCP Socket on Alpine Linux

To allow the Gitea Actions runner (or your local machine) to deploy to the remote Alpine host, you must configure the Docker daemon to listen on the TCP socket:

1. Edit `/etc/conf.d/docker` on the Alpine host:

   ```bash
   vi /etc/conf.d/docker
   ```

2. Update the `DOCKER_OPTS` line to include both the unix socket and the TCP socket:

   ```bash
   DOCKER_OPTS="-H unix:///var/run/docker.sock -H tcp://0.0.0.0:2375"
   ```

3. Restart the Docker service:

   ```bash
   rc-service docker restart
   ```

4. Verify that Docker is listening on port `2375`:

   ```bash
   netstat -tlnp | grep 2375
   ```

5. Ensure any firewall (like `awall` or `iptables`) on the Alpine host allows incoming traffic on port `2375` from your local network subnet (e.g., `192.168.88.0/24`).

#### Deployment Steps

1. **Configure Docker CLI to use the Remote Host**:
   You can point your local Docker CLI to the remote server by setting the `DOCKER_HOST` environment variable:
   - **PowerShell (Windows)**:

     ```powershell
     $env:DOCKER_HOST="tcp://192.168.88.40:2375"
     ```

   - **Bash (Linux/macOS)**:

     ```bash
     export DOCKER_HOST="tcp://192.168.88.40:2375"
     ```

2. **Verify Connection**:
   Run `docker info` to confirm your local CLI is communicating with the remote server at `192.168.88.40`:

   ```bash
   docker info
   ```

   The output should show the remote server's hostname and system details.

3. **Deploy the Stack**:
   With `DOCKER_HOST` set, any `docker` or `docker compose` commands you run locally will execute directly on the remote server.
   - **Deploy from Registry (Production-like)**:

     ```bash
     docker compose -f docker-compose.prod.yml pull
     docker compose -f docker-compose.prod.yml up -d --remove-orphans
     ```

   - **Build and Deploy from Source**:

     ```bash
     docker compose up -d --build
     ```

4. **Access the Test Environment**:
   - Playout Health: `http://192.168.88.40:8081/health`
   - Chat Health: `http://192.168.88.40:3000/health`
   - Nginx Entrypoint: `http://192.168.88.40:8080` (or the port mapped to `NGINX_PORT` in `.env`)

5. **Reset to Local Docker Host**:
   Once testing is complete, clear the `DOCKER_HOST` variable to point back to your local machine:
   - **PowerShell**:

     ```powershell
     Remove-Item env:DOCKER_HOST
     ```

   - **Bash**:

     ```bash
     unset DOCKER_HOST
     ```

### Coolify Deployment

Coolify is an open-source, self-hostable PaaS (Heroku/Netlify/Vercel
alternative) that can deploy the Linear Void stack through a web UI with
automatic HTTPS and one-click redeploys. It replaces the deployment
orchestration layer (the Gitea CD `DOCKER_HOST` flow) while leaving Cloudflare
DNS, R2 media, and cache rules unchanged.

To deploy via Coolify:

1. **Install Coolify** on a dedicated server:

   ```bash
   curl -fsSL https://cdn.coollabs.io/coolify/install.sh | bash
   ```

2. **Add the target server** in the dashboard via SSH (or use Localhost if
   Coolify runs on the same machine as the stack).
3. **Create a Docker Compose resource** pointing at either the Git repository
   (`docker-compose.prod.yml`) or the compose file contents directly.
4. **Configure environment variables** in Coolify's secret store (the values
   normally held in `.env`), keeping internal URLs on compose hostnames
   (`redis`, `db`).
5. **Map persistent storage** for `data/` mounts and the `redis-data` /
   `postgres-data` named volumes so data survives redeploys.
6. **Assign a domain** to the nginx service so Coolify's Traefik proxy
   terminates TLS for `linearvoid.tv`, while `media.linearvoid.tv` continues to
   serve HLS from Cloudflare R2.

For the full walkthrough, environment-variable table, verification steps, and
cutover notes, see [COOLIFY.md](./COOLIFY.md).

### Production Setup Guide

1. **Prepare the target host**:
   - Provision a Linux VPS with Docker Engine, Docker Compose, Git, and enough disk for media, HLS output, PostgreSQL, Redis persistence, and monitoring data.
   - Open the ports required for HTTP/HTTPS and any restricted monitoring access you intend to expose.

2. **Clone the repository and create the environment file**:

   ```bash
   git clone https://git.allucanget.biz/zwitschi/linearvoid.git
   cd linearvoid
   cp .env.example .env
   ```

3. **Set production-safe `.env` values**:
   - Replace placeholder secrets.
   - Use compose-network hostnames for internal services, for example `redis` and `db`.
   - Set strong values for `POSTGRES_PASSWORD` and `GRAFANA_PASSWORD`.
   - Keep `MEDIA_DOMAIN`, R2 credentials, and Gitea registry values consistent with the external infrastructure.
   - Set `MEDIA_DOMAIN=media.linearvoid.tv`.
   - Set `VITE_PUBLIC_APP_URL=https://linearvoid.tv`, `VITE_PUBLIC_WS_URL=wss://linearvoid.tv/ws`, and `VITE_PUBLIC_HLS_URL=https://media.linearvoid.tv/hls/playlist.m3u8`.
   - If you intentionally bypass the public proxy for local-only testing, switch those values to `http://localhost`, `ws://localhost/ws`, and `http://localhost/hls/playlist.m3u8`.

4. **Create runtime directories on the server**:

   ```bash
   mkdir -p data/playlist data/media data/hls data/chat
   ```

5. **Publish or verify required images in Gitea**:
   - Ensure the `playout`, `chat`, and `nginx` images exist under `${CI_REGISTRY_URL}/${CI_REGISTRY_NAMESPACE}`.
   - Log in to the registry from the VPS before pulling.

6. **Deploy the production stack**:

   ```bash
   docker compose -f docker-compose.prod.yml pull
   docker compose -f docker-compose.prod.yml up -d
   ```

7. **Run post-deploy verification**:
   - Check `docker compose -f docker-compose.prod.yml ps`.
   - Confirm nginx, chat, and playout health endpoints respond.
   - Verify that HLS output is being written to `data/hls` and that the media domain serves manifests and segments through Cloudflare.

8. **Harden and operate the deployment**:
   - Put HTTPS in front of nginx using Cloudflare or another reverse proxy, with `linearvoid.tv` as canonical app host and `www.linearvoid.tv` redirected.
   - Restrict Grafana and Prometheus exposure to trusted IPs or a private network.
   - Run the stack under systemd or another service manager if you need auto-start behavior outside Docker restart policies.

### Production Deployment (Hetzner VPS + Cloudflare)

1. **Provision VPS**: Use Hetzner Cloud CX22 in Ashburn, VA (per ADR-001).
2. **Configure Cloudflare**:
   - Create R2 bucket with `enam` location hint.
   - Set up custom media domain (`media.linearvoid.tv`) with the cache rules from [cache-rules](../docs/infrastructure/cloudflare/cache-rules.md).
   - Point `linearvoid.tv` and `www.linearvoid.tv` at the app entrypoint, then redirect `www` to the apex domain.
   - Use Full (strict) TLS for both app and media hostnames.
   - Apply the Worker from `infrastructure/cloudflare/worker.js` for advanced header management.
3. **Deploy**:
   - Copy the project to the VPS.
   - Use production compose: `docker compose -f docker-compose.prod.yml up -d`
   - Or pull from Gitea registry: `docker compose -f docker-compose.prod.yml pull && docker compose -f docker-compose.prod.yml up -d`
   - Configure systemd to manage the Docker Compose stack.
4. **Monitoring**: Access Grafana at the exposed port for dashboards (included in `monitoring/grafana/dashboard.json`).

See `docs/architecture/README.md` for the full arc42 documentation and the ADRs for architectural decisions.

## Troubleshooting

- **R2 Upload Fails**: Check credentials in `.env` and ensure the bucket exists. Verify with `aws s3 ls --endpoint-url=$R2_ENDPOINT`.
- **Normalization Errors**: Run `backend/playout/start-playout.sh` manually to see ffprobe output. All videos must be H.264/AAC, 30 fps constant, 2s keyframes (ADR-001).
- **Chat Not Connecting**: Check Redis connection and WebSocket URL. The health check at `/health` should return 200.
- **Cache Not Working**: Verify Cloudflare cache rules (`.m4s` = long TTL immutable, `.m3u8` = short TTL). Check cache hit ratio in Cloudflare dashboard.
- **Docker Issues**: Run `docker compose logs` for service-specific errors. Ensure ports are not in use.
- **Admin Interface**: Ensure `ADMIN_USERNAME`, `ADMIN_PASSWORD`, and `ADMIN_SESSION_TTL_HOURS` are set. `/admin/` and `/api/admin/*` are protected by a session-based login flow.
- **Production Pull Fails**: Confirm `docker login` to Gitea succeeded on the server and the image tags referenced by `docker-compose.prod.yml` exist.

## Further Reading

- Architecture: `docs/architecture/README.md` (arc42 template with diagrams).
- Decisions: `docs/architecture/adr/` (ADR-001 to ADR-007).
- Contributing: `CONTRIBUTING.md`.
- Project Structure: Root `README.md`.

The system is ready for use. For production, review ADR-001 for cost estimates and scaling guidance.