feat: add NATS + Dapr infrastructure for event-driven architecture

- infra/compose/nats.yml: NATS server with JetStream, persistence volume, healthcheck
- infra/compose/dapr.yml: Dapr placement service for sidecar coordination
- infra/dapr/: Dapr global config, pubsub component (NATS), statestore (Redis)
- infra/compose/scraper.yml: add Dapr sidecar container + depends_on nats/dapr
- docs/add-dapr-service.md: guide for integrating Dapr into new services
- docs/add-new-app.md: add Dapr sidecar step
- ARCHITECTURE.md: add NATS/Dapr to infra table + service mesh diagram
- infra/README.md: update layout and deployment order
- deploy-docker.yml: add nats.yml + dapr.yml to ALL_COMPOSE_FILES

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

infra/README.md

@@ -9,16 +9,19 @@ infra/
 ├── compose/                 # One compose file per stack/service
 │   ├── traefik.yml          # Public reverse proxy
 │   ├── shared.yml           # Shared Redis
-│   └── scraper.yml          # Scraper API
+│   ├── nats.yml             # NATS message broker + JetStream
+│   ├── dapr.yml             # Dapr placement service
+│   └── scraper.yml          # Scraper API (app + Dapr sidecar)
 ├── docker/                  # Dockerfiles and image runtime helpers
+├── dapr/                    # Dapr component configs
+│   ├── config.yaml          # Global Dapr configuration
+│   └── components/          # Pub/sub (NATS), state store (Redis)
 ├── traefik/                 # Static and dynamic Traefik configuration
 │   ├── dynamic/             # Routers, services, middlewares, TLS certs
 │   └── TRAEFIK_ENV_CONFIG.md
 └── config/                  # Service bootstrap configuration
 ```
 
-Archived configs that are not deployed live under `docs/config/`.
-
 ## First-time setup
 
 Create the shared Docker network before starting any service:
@@ -34,12 +37,18 @@ Create `.env` from `.env.example` and fill production values. Do not commit `.en
 The GitHub deploy workflow combines the active compose files automatically. For manual deployment, use this order:
 
 ```bash
+# 1. Shared services
 docker compose -f infra/compose/shared.yml up -d
+
+# 2. Message bus + Dapr placement
+docker compose -f infra/compose/nats.yml up -d
+docker compose -f infra/compose/dapr.yml up -d
+
+# 3. Reverse proxy
 docker compose -f infra/compose/traefik.yml up -d
 
-docker compose \
-  -f infra/compose/scraper.yml \
-  up -d
+# 4. Application services (with Dapr sidecars)
+docker compose -f infra/compose/scraper.yml up -d
 ```
 
 ## Environment variables