feat(ci): add receiptwitness build job to monorepo CI

receiptwitness/Dockerfile

@@ -3,24 +3,21 @@ FROM python:3.12-slim AS build
 
 WORKDIR /app
 
-# git is required to install cartsnitch-common from GitHub; build-essential and
-# libpq-dev are needed to compile any C-extension wheels (e.g. psycopg2 fallback)
+# build-essential and libpq-dev are needed to compile any C-extension wheels
+# (e.g. psycopg2 fallback).  No git needed — common/ is copied from the repo root.
 RUN apt-get update && apt-get install -y --no-install-recommends \
-    git \
     libpq-dev \
     build-essential \
     && rm -rf /var/lib/apt/lists/*
 
-COPY pyproject.toml ./
-COPY src/ ./src/
+# Build context is the repo root.  These paths are relative to the root.
+COPY receiptwitness/pyproject.toml ./
+COPY receiptwitness/src/ ./src/
+COPY common/ ./common/
 
-# cartsnitch-common is not on PyPI — install it directly from GitHub, then
-# install the rest of the package dependencies in a single resolver pass so
-# pip can satisfy the cartsnitch-common>=0.1.0 constraint declared in
-# pyproject.toml without hitting PyPI for it.
-RUN pip install --no-cache-dir --prefix=/install \
-    "cartsnitch-common @ git+https://github.com/cartsnitch/common.git@76685ed0384103228cd670b477b967e7752ebe6b" \
-    .
+# Install from the local common/ (cartsnitch-common>=0.1.0 in pyproject.toml
+# will be satisfied by the local package) then install receiptwitness itself.
+RUN pip install --no-cache-dir --prefix=/install ./common/ .
 
 # Stage 2: Production image with Playwright + Chromium
 FROM python:3.12-slim AS prod
@@ -51,7 +48,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 RUN adduser --system --group --uid 1000 app
 
 COPY --from=build /install /usr/local
-COPY src/ ./src/
+COPY receiptwitness/src/ ./src/
 
 # Install Playwright Chromium browser (runs as root; /opt/playwright is world-readable)
 RUN PLAYWRIGHT_BROWSERS_PATH=/opt/playwright playwright install chromium