fix(pages): build registry to web root so items serve at /r/<name>.json

`slintcn build` writes the index to <out>/registry.json and items to
<out>/r/*.json. Deploying with -o web/r double-nested items at /r/r/*.json;
-o web puts the index at /registry.json and items at /r/<name>.json — the URL
the README documents for remote install.

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

Author: stevekwon211

.github/workflows/pages.yml

@@ -57,8 +57,8 @@ jobs:
         with:
           node-version: 20
 
-      - name: Build static registry (served at /r/<name>.json)
-        run: node bin/slintcn.mjs build -o web/r
+      - name: Build static registry (index at /registry.json, items at /r/<name>.json)
+        run: node bin/slintcn.mjs build -o web
 
       - name: Upload Pages artifact
         uses: actions/upload-pages-artifact@v3

.gitignore

@@ -25,4 +25,5 @@ slint-build-*.log
 web/pkg/
 # static registry built by `slintcn build` (regenerated for Pages + npm)
 web/r/
+web/registry.json
 dist/