Build CI scripts into test-runner image instead of volume mount

DinD volume mounts don't work — the Docker daemon can't see the CI
runner's workspace volume. Instead, COPY ci/ into the Playwright
image at build time via dockerfile_inline. No volume detection needed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docker-compose.ci.yml

@@ -25,20 +25,20 @@ services:
       start_period: 5s
 
   test-runner:
-    image: mcr.microsoft.com/playwright:v1.52.0-noble
+    build:
+      context: .
+      dockerfile_inline: |
+        FROM mcr.microsoft.com/playwright:v1.52.0-noble
+        RUN npm install --no-save playwright 2>/dev/null
+        WORKDIR /work
+        COPY ci/ /work/ci/
+        RUN chmod +x /work/ci/*.sh
     depends_on:
       armature:
         condition: service_healthy
     working_dir: /work
-    volumes:
-      - ${CI_WORKSPACE_VOLUME:-.}:/work
     environment:
       SERVER_URL: http://armature:80
       ADMIN_USER: admin
       ADMIN_PASS: admin
-    command:
-      - bash
-      - -c
-      - |
-        npm install --no-save playwright 2>/dev/null
-        ./ci/run-surface-tests.sh
+    command: ["bash", "-c", "./ci/run-surface-tests.sh"]