fix(webapp): make prop-types a production dependency

The server bundle imports prop-types directly, so it has to be present in a
production install. It was declared only as a devDependency, so `pnpm install
--prod` leaves it out and the built server fails to boot with
ERR_MODULE_NOT_FOUND on startup.

Nothing in the webapp's own code imports it. It arrives through recharts, whose
react-smooth dependency declares propTypes on its components. That used to be
invisible here: while recharts was resolved at runtime, the import was satisfied
inside recharts' own dependency tree. #4486 added recharts to `ssr.noExternal`
to fix a hydration mismatch, which inlines react-smooth into the server bundle
and moves its prop-types import into the webapp's own resolution scope, where the
package was not available in production.

Verified by pruning the workspace the way docker/Dockerfile does and running
`pnpm install --prod` against it: importing prop-types from the webapp fails
with ERR_MODULE_NOT_FOUND before this change and resolves after. It is the only
devDependency-only bare import in the server bundle, out of 169 specifiers.

Author: ericallam

apps/webapp/package.json

@@ -179,6 +179,7 @@
     "prism-react-renderer": "^2.3.1",
     "prismjs": "^1.30.0",
     "prom-client": "^15.1.0",
+    "prop-types": "^15.8.1",
     "qrcode.react": "^4.2.0",
     "random-words": "^2.0.0",
     "react": "^18.2.0",
@@ -260,7 +261,6 @@
     "npm-run-all": "^4.1.5",
     "postcss-import": "^16.0.1",
     "postcss-loader": "^8.1.1",
-    "prop-types": "^15.8.1",
     "rimraf": "^6.0.1",
     "style-loader": "^3.3.4",
     "supertest": "^7.0.0",