revert: remove ELO rank feature (data source inaccessible)

stat-check.com's ELO data is behind Microsoft auth with no public
API or download endpoint available. Removing the sync script,
placeholder JSON, CI job, table column, and all related JS.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitlab-ci.yml

@@ -1,33 +1,7 @@
 stages:
-  - sync
   - build
   - deploy
 
-# Runs only on scheduled pipelines (every Wednesday via GitLab schedule).
-# Downloads the stat-check.com ELO Excel sheet, writes public/elo-data.json,
-# then commits and pushes so a normal build+deploy pipeline picks it up.
-# Requires CI variable: GITLAB_PUSH_TOKEN (project token, write_repository scope)
-sync-elo:
-  stage: sync
-  only:
-    - schedules
-  script:
-    - pip3 install --break-system-packages requests openpyxl -q
-    - python3 scripts/sync-elo.py
-    - git config user.email ci@gateway-gamers.net
-    - 'git config user.name "GG CI Bot"'
-    - 'git remote set-url origin "https://oauth2:${GITLAB_PUSH_TOKEN}@gl.mando.club/mandalore/40k-rankings.gateway-gamers.net.git"'
-    - git add public/elo-data.json
-    - |
-      if git diff --staged --quiet; then
-        echo "No ELO changes, skipping commit."
-      else
-        git commit -m 'sync: update ELO data'
-        git push origin HEAD:main
-      fi
-
-# Build and deploy skip on scheduled pipelines — the robot push above
-# triggers its own normal pipeline that handles the actual build + deploy.
 build:
   stage: build
   script:
@@ -39,8 +13,6 @@ build:
     expire_in: 1 hour
   only:
     - main
-  except:
-    - schedules
 
 deploy:
   stage: deploy
@@ -48,8 +20,6 @@ deploy:
     - rsync -avz --delete dist/ /var/www/domains/gateway-gamers.net/40k-rankings/
   only:
     - main
-  except:
-    - schedules
   environment:
     name: production
     url: https://40k-rankings.gateway-gamers.net