fix(ci): derive Railway preview URLs from env name

.github/workflows/e2e-pr.yml

@@ -22,26 +22,36 @@ jobs:
       - run: pnpm install --frozen-lockfile
       - run: npx playwright install --with-deps chromium
 
-      - name: Extract PR number
-        id: meta
-        run: |
-          ENV="${{ github.event.deployment.environment }}"
-          PR_NUMBER=$(echo "$ENV" | grep -oP '(?<=pr-)\d+' || true)
-          if [ -z "$PR_NUMBER" ]; then
-            echo "::error::Could not parse PR number from environment: $ENV"
-            exit 1
-          fi
-          echo "pr_number=$PR_NUMBER" >> $GITHUB_OUTPUT
-
       - name: Derive service URLs
         id: urls
         env:
-          PR: ${{ steps.meta.outputs.pr_number }}
+          # "ePDS / ePDS-pr-48" for normal envs, "ePDS / pr-3897f1-47" when
+          # Railway falls back to its collision-avoidance naming during a
+          # close/reopen or force-push that hits the env-cleanup window.
+          # See: https://station.railway.com/questions/pr-environment-name-format-change-causin-9aaa904f
+          FULL_ENV: ${{ github.event.deployment.environment }}
         run: |
-          echo "epds_url=https://certified-apppds-core-epds-pr-${PR}.up.railway.app" >> $GITHUB_OUTPUT
-          echo "auth_url=https://certified-appauth-service-epds-pr-${PR}.up.railway.app" >> $GITHUB_OUTPUT
-          echo "demo_url=https://certified-appdemo-epds-pr-${PR}.up.railway.app" >> $GITHUB_OUTPUT
-          echo "mailpit_url=https://mailpit-epds-pr-${PR}.up.railway.app" >> $GITHUB_OUTPUT
+          # Railway's autogenerated *.up.railway.app domains are built as
+          # <service-slug>-<env-name>.up.railway.app, with both parts lowercased
+          # and the scope prefix stripped from the service name. Derive URLs
+          # from the live env name rather than templating off the PR number,
+          # so both naming formats work without a Railway API lookup.
+          if [[ "$FULL_ENV" != *" / "* ]]; then
+            echo "::error::Unexpected deployment environment format: $FULL_ENV"
+            exit 1
+          fi
+          ENV_NAME="${FULL_ENV##* / }"
+          ENV_SLUG="${ENV_NAME,,}"
+          if [[ -z "$ENV_SLUG" || ! "$ENV_SLUG" =~ ^[a-z0-9][a-z0-9-]*$ ]]; then
+            echo "::error::Could not parse env name from deployment environment: $FULL_ENV"
+            exit 1
+          fi
+          {
+            echo "epds_url=https://certified-apppds-core-${ENV_SLUG}.up.railway.app"
+            echo "auth_url=https://certified-appauth-service-${ENV_SLUG}.up.railway.app"
+            echo "demo_url=https://certified-appdemo-${ENV_SLUG}.up.railway.app"
+            echo "mailpit_url=https://mailpit-${ENV_SLUG}.up.railway.app"
+          } >> "$GITHUB_OUTPUT"
 
       - name: Wait for all services
         run: |