refactor: move deployment files from web/ to repo root

Moves Dockerfile, docker-compose.yml, docker-compose.prod.yml, deploy.sh,
litestream.yml, and router/ from web/ to the monorepo root so copier update
can manage them from the template.

Dockerfile updated for monorepo layout:
- CSS build stage: COPY web/src/ ./web/src/ (Tailwind input path updated)
- Python build stage: copies root uv.lock + web/pyproject.toml separately,
  runs `uv sync --package beanflows` (not full workspace sync)
- Runtime CSS copy path updated to web/src/beanflows/static/css/output.css

deploy.sh: fixed sops path ($APP_DIR/.env.prod.sops, was $APP_DIR/../)

supervisor.py:
- web_code_changed(): Dockerfile path is now root-level (was web/Dockerfile)
- tick(): deploy script is now ./deploy.sh (was ./web/deploy.sh)

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

router/default.conf

@@ -0,0 +1,15 @@
+upstream app {
+    server blue-app:5000;
+}
+
+server {
+    listen 80;
+
+    location / {
+        proxy_pass http://app;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+    }
+}