fix: update Dockerfile to set correct working directory for migrations

migrations/Dockerfile

@@ -1,7 +1,7 @@
 # syntax=docker/dockerfile:1.7
 
 FROM ghcr.io/astral-sh/uv:python3.14-alpine AS builder
-WORKDIR /opt/migrations
+WORKDIR /opt/app
 
 COPY pyproject.toml uv.lock ./
 RUN uv sync --frozen --no-dev
@@ -11,8 +11,10 @@ COPY migrations ./migrations
 COPY alembic.ini .
 
 FROM python:3.14-alpine AS runtime
+
 ENV PYTHONUNBUFFERED=1 PYTHONDONTWRITEBYTECODE=1
 ENV PATH="/opt/app/.venv/bin:${PATH}"
+
 WORKDIR /opt/app
 
 RUN apk add --no-cache libpq