Make the app's port configurable via DEVPLACE_PORT

make dev/prod hardcoded uvicorn to port 10500 with no way to override it,
so config.PORT (and everything derived from it - INTERNAL_BASE_URL,
Devii's own base URL defaults) stayed 10500 regardless of what port the
process actually bound to. DEVPLACE_PORT now drives all of it, defaulting
to 10500. Docker's existing PORT var (the externally published port via
nginx) is unrelated and untouched; its app container pins DEVPLACE_PORT
to 10500 explicitly so a bare-metal .env value can never leak in and
desync it from the Dockerfile's fixed internal bind port.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docker-compose.yml

@@ -13,6 +13,10 @@ services:
     environment:
       HOME: /app
       PYTHONDONTWRITEBYTECODE: "1"
+      # Pinned regardless of .env: the container always binds 10500 internally
+      # (Dockerfile CMD, nginx upstream). DEVPLACE_PORT is the bare-metal
+      # `make dev`/`make prod` knob; the externally reachable port is `PORT`.
+      DEVPLACE_PORT: "10500"
     volumes:
       - .:/app
     expose: