chore: remove Next.js and repoint CI at the SvelteKit layout

sync-data.yml now writes static/champions.json. This is the edit that had to
land with the deletion of public/: the workflow reports success regardless of
which path it writes, so a miss would have left the weekly sync green while
the live game 404'd on data load.

deploy.yml publishes build/ and passes BASE_PATH. Adds ci.yml, which runs
test, lint, and build on pull_request and pushes to main -- the repo had no
PR-triggered workflow before, so 'green before merge' was previously
unenforceable.

Deletes app/, components/, lib/, public/, next.config.mjs and
postcss.config.mjs, drops the Next and React dependencies, and swaps ESLint
onto eslint-plugin-svelte. sharp and unrs-resolver left pnpm's allowBuilds
because both arrived with Next and pnpm why now reports no dependents.

web/.github/workflows/ci.yml

@@ -0,0 +1,36 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+
+      - uses: pnpm/action-setup@v6
+
+      - uses: actions/setup-node@v7
+        with:
+          node-version: '24'
+          cache: 'pnpm'
+
+      - run: pnpm install --frozen-lockfile --ignore-scripts
+
+      - run: pnpm test
+
+      - run: pnpm lint
+
+      # No BASE_PATH here: this checks that the app compiles. The base-path
+      # behaviour is verified against a real preview before release.
+      - run: pnpm build

web/.github/workflows/deploy.yml

@@ -31,11 +31,11 @@ jobs:
 
       - run: pnpm build
         env:
-          NEXT_PUBLIC_BASE_PATH: /${{ github.event.repository.name }}
+          BASE_PATH: /${{ github.event.repository.name }}
 
       - uses: actions/upload-pages-artifact@v5
         with:
-          path: out
+          path: build
 
   deploy:
     needs: build

web/.github/workflows/sync-data.yml

@@ -29,20 +29,20 @@ jobs:
           set -euo pipefail
           sha=$(gh api "repos/$SOURCE_REPO/commits/main" --jq .sha)
           gh api "repos/$SOURCE_REPO/contents/champions.json?ref=$sha" \
-            -H "Accept: application/vnd.github.raw" > public/champions.json
+            -H "Accept: application/vnd.github.raw" > static/champions.json
           echo "SOURCE_SHA=${sha:0:7}" >> "$GITHUB_ENV"
 
       - name: Commit if changed
         id: commit
         run: |
           set -euo pipefail
-          if git diff --quiet -- public/champions.json; then
-            echo "public/champions.json already matches loldle-data@$SOURCE_SHA"
+          if git diff --quiet -- static/champions.json; then
+            echo "static/champions.json already matches loldle-data@$SOURCE_SHA"
             exit 0
           fi
           git config user.name "github-actions[bot]"
           git config user.email "github-actions[bot]@users.noreply.github.com"
-          git add public/champions.json
+          git add static/champions.json
           git commit -m "chore(data): sync champions from loldle-data@$SOURCE_SHA"
           git push
           echo "changed=true" >> "$GITHUB_OUTPUT"