fix(db): add missing apiKeys columns + restore ApiExplorerModal export

- schema.js: add createdAt/allowedModels to apiKeys, bump SCHEMA_VERSION 3->4
- shared/components/index.js: restore ApiExplorerModal barrel export (was replaced by TagInput)
- combos: tag support, repo + api + page updates

tmp/9r-smoke-dist/dev/static/development/_buildManifest.js

@@ -0,0 +1,44 @@
+self.__BUILD_MANIFEST = {
+  "__rewrites": {
+    "afterFiles": [
+      {
+        "source": "/v1/v1/:path*",
+        "destination": "/api/v1/:path*"
+      },
+      {
+        "source": "/v1/v1",
+        "destination": "/api/v1"
+      },
+      {
+        "source": "/codex/:path*",
+        "destination": "/api/v1/responses"
+      },
+      {
+        "source": "/responses",
+        "destination": "/api/v1/responses"
+      },
+      {
+        "source": "/v1beta/:path*",
+        "destination": "/api/v1beta/:path*"
+      },
+      {
+        "source": "/v1beta",
+        "destination": "/api/v1beta"
+      },
+      {
+        "source": "/v1/:path*",
+        "destination": "/api/v1/:path*"
+      },
+      {
+        "source": "/v1",
+        "destination": "/api/v1"
+      }
+    ],
+    "beforeFiles": [],
+    "fallback": []
+  },
+  "sortedPages": [
+    "/_app",
+    "/_error"
+  ]
+};self.__BUILD_MANIFEST_CB && self.__BUILD_MANIFEST_CB()