Add sx documentation app (sx.rose-ash.com)

New public-facing service documenting the s-expression rendering engine.
Modelled on four.htmx.org with violet theme, all content rendered via sx.

Sections: docs, reference, protocols, examples (live demos), essays
(including "sx sucks"). No database — purely static documentation.

Port 8012, Redis DB 10. CI and deploy.sh updated with app_dir() mapping
for sx_docs -> sx/ directory. Caddy reverse proxy entry added separately.

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

docker-compose.dev.yml

@@ -378,6 +378,43 @@ services:
       - ./likes:/app/likes:ro
       - ./orders:/app/orders:ro
 
+  sx_docs:
+    restart: unless-stopped
+    ports:
+      - "8012:8000"
+    environment:
+      <<: *dev-env
+    volumes:
+      - /root/rose-ash/_config/app-config.yaml:/app/config/app-config.yaml:ro
+      - ./shared:/app/shared
+      - ./sx/app.py:/app/app.py
+      - ./sx/sxc:/app/sxc
+      - ./sx/bp:/app/bp
+      - ./sx/services:/app/services
+      - ./sx/content:/app/content
+      - ./sx/path_setup.py:/app/path_setup.py
+      - ./sx/entrypoint.sh:/usr/local/bin/entrypoint.sh
+      - ./sx/__init__.py:/app/__init__.py:ro
+      # sibling models
+      - ./blog/__init__.py:/app/blog/__init__.py:ro
+      - ./blog/models:/app/blog/models:ro
+      - ./market/__init__.py:/app/market/__init__.py:ro
+      - ./market/models:/app/market/models:ro
+      - ./cart/__init__.py:/app/cart/__init__.py:ro
+      - ./cart/models:/app/cart/models:ro
+      - ./events/__init__.py:/app/events/__init__.py:ro
+      - ./events/models:/app/events/models:ro
+      - ./federation/__init__.py:/app/federation/__init__.py:ro
+      - ./federation/models:/app/federation/models:ro
+      - ./account/__init__.py:/app/account/__init__.py:ro
+      - ./account/models:/app/account/models:ro
+      - ./relations/__init__.py:/app/relations/__init__.py:ro
+      - ./relations/models:/app/relations/models:ro
+      - ./likes/__init__.py:/app/likes/__init__.py:ro
+      - ./likes/models:/app/likes/models:ro
+      - ./orders/__init__.py:/app/orders/__init__.py:ro
+      - ./orders/models:/app/orders/models:ro
+
   test-unit:
     build:
       context: .