ci: exclude public/ from Biome and disable automerge for Biome updates

Biome 2.5.7 (auto-merged by Renovate in #904 with failing checks) started
parsing SVG files, breaking lint on generated assets in public/. Exclude
the whole public/ directory instead of just *.svg so future parser
changes can't hit generated files again.

Biome minor updates can also introduce new lint rules for source code,
so require manual review for its Renovate PRs instead of automerge.

.github/renovate.json

@@ -33,6 +33,11 @@
             "matchPackagePatterns": ["@ai-sdk/*", "ai", "next"],
             "groupName": "Core framework packages",
             "automerge": false
+        },
+        {
+            "matchPackageNames": ["@biomejs/biome"],
+            "groupName": "Biome",
+            "automerge": false
         }
     ],
     "vulnerabilityAlerts": {

biome.json

@@ -7,7 +7,7 @@
     },
     "files": {
         "ignoreUnknown": false,
-        "includes": ["**", "!public/**/*.svg"]
+        "includes": ["**", "!public"]
     },
     "formatter": {
         "enabled": true,