refactor: give the frontend its own directory and split the API into routers

The Site's page sat at the repository root while its scripts lived in
local/static, a split with no reason behind it. They are together in web/ now,
with the page as index.html, which is also what the image serves.

app.py held the adapters, the configuration, the shared query helpers and
nineteen routes; customer.py held fourteen more but could not import from it
without a cycle, so it was wired by passing nine callables into install_routes.
Configuration and shared helpers move to local/runtime.py, the rules for
attaching artwork to an order move to local/artwork.py where a customer
correction and an operator final-file set can share them, and the routes become
seven routers under local/api. app.py is 48 lines that create the application,
apply the middleware and include them. Routers import downwards only.

Three faults came out of the extraction and are worth recording, because each
passed a check that looked sufficient. ast reports a function's line at the def,
so every decorator on the line above fell outside the extracted range: twelve
routes and the security middleware were defined but never registered, and the
files still imported and parsed cleanly. Names the old closure renamed on the
way in, and a Jsonb import, were missing in three modules. A name-resolution
pass over every new module found those; the route count matching the original
exactly, 32, is what confirmed the first.

The release gate's marker for the fake payment adapter pointed at app.py and the
adapter moved to runtime.py, so the gate passed while the condition it guards was
unchanged. That is the same silent decay 2.5 set out to fix. A test now asserts
every marker still matches something in its file, so the next move fails loudly.

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

deploy/Dockerfile.web

@@ -7,7 +7,7 @@ ARG PYTHON_BASE_IMAGE=python:3.12-slim@sha256:2f17fc044b579bab302c2e8054d3a686e2
 ARG NGINX_BASE_IMAGE=nginx:alpine@sha256:62ff2089abf5a9ed33bd232895bef5e22f7bb4b200675cec49a5ebc48e3d4ac8
 FROM ${PYTHON_BASE_IMAGE} AS policy
 WORKDIR /build
-COPY dtf-site.html /build/dtf-site.html
+COPY web /build/web
 COPY local /build/local
 COPY deploy /build/deploy
 ENV NGINX_TEMPLATE=/build/deploy/nginx.conf.template
@@ -22,8 +22,8 @@ LABEL org.opencontainers.image.title="DTF Site and Kanban" \
       org.opencontainers.image.source="DTF System repository"
 ENV WEB_INDEX=index.html PUBLIC_HOST=invalid.example S3_PUBLIC_ENDPOINT=https://invalid.example
 COPY --from=policy /build/default.conf.template /etc/nginx/templates/default.conf.template
-COPY dtf-site.html /usr/share/nginx/html/index.html
-COPY local/static/ /usr/share/nginx/html/
+COPY web/ /usr/share/nginx/html/
+
 # The official entrypoint renders the server configuration at startup and Nginx
 # writes its PID/cache files.  Keep the service non-root while granting it
 # ownership of only those runtime locations.  This works in Docker Swarm,