chore(lint): add perf category to oxlint and fix resulting warnings

- Enable `perf: warn` in `.oxlintrc.json` and add `builtin` env; disable `no-await-in-loop` and `react/no-array-index-key` globally
- Reorder plugins so `oxc` is first
- Add `.oxfmtrc.json` override to suppress trailing commas in JSON/JSONC files
- Replace spread-into-new-object patterns (`{ ...x, key: val }`) with `Object.assign(x, { key: val })` in discover, explore, integrations, search, credits, and image-cache to satisfy perf rules
- Memoize `ChartContext` and `ToggleGroupContext` provider values to avoid unnecessary re-renders

.oxfmtrc.json

@@ -38,6 +38,14 @@
     ],
     "functions": ["cn", "clsx", "cva", "useResolveClassNames"]
   },
+  "overrides": [
+    {
+      "files": ["**/*.json", "**/*.jsonc"],
+      "options": {
+        "trailingComma": "none"
+      }
+    }
+  ],
   "ignorePatterns": [
     "node_modules",
     "dist",