ci: allow esbuild/@swc native build scripts under pnpm 10

The fedora-44 runner's pnpm 10 blocks dependency build scripts by default,
so `pnpm install` failed the web build with ERR_PNPM_IGNORED_BUILDS. esbuild
and @swc/core need their postinstall to place native binaries for vite; allow
them via pnpm.onlyBuiltDependencies, and explicitly ignore the harmless
react-vertical-timeline-component postinstall. Does not change the lockfile.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01X7zF7Kf4JqDwa6M8Qgge9M

ui/package.json

@@ -33,5 +33,14 @@
     "@vitejs/plugin-react-swc": "^3.7.2",
     "typescript": "~5.7.0",
     "vite": "^6.0.0"
+  },
+  "pnpm": {
+    "onlyBuiltDependencies": [
+      "@swc/core",
+      "esbuild"
+    ],
+    "ignoredBuiltDependencies": [
+      "react-vertical-timeline-component"
+    ]
   }
 }