mount to more reasonable place and update docs comments

.github/workflows/build-notebooks-TEMPLATE.yaml

@@ -222,8 +222,12 @@ jobs:
       - name: Run Playwright tests
         if: ${{ fromJson(inputs.github).event_name == 'pull_request' && contains(inputs.target, 'codeserver') }}
         # --ipc=host because Microsoft says so in Playwright docs
-        # --net=host because tests connect to the Reaper image
+        # --net=host because testcontainers connects to the Reaper container's exposed port
         # we need to pass through the relevant environment variables
+        #  DEBUG configures nodejs debuggers, sets different verbosity as needed
+        #  CI=true is set on every CI nowadays
+        #  PODMAN_SOCK should be mounted to /var/run/docker.sock, other likely mounting locations may not exist (mkdir -p)
+        #  TEST_TARGET is the workbench image the test will run
         # --volume(s) let us access docker socket and not clobber host's node_modules
         run: |
           podman run \
@@ -232,9 +236,9 @@ jobs:
             --net=host \
             --env "DEBUG=testcontainers:*" \
             --env "CI=true" \
-            --env "PODMAN_SOCK" \
+            --env "PODMAN_SOCK=/var/run/docker.sock" \
             --env "TEST_TARGET" \
-            --volume ${PODMAN_SOCK}:${PODMAN_SOCK} \
+            --volume ${PODMAN_SOCK}:/var/run/docker.sock \
             --volume ${PWD}:/mnt \
             --volume /mnt/node_modules \
             mcr.microsoft.com/playwright:v1.48.1-noble \