fix: use bun --cwd to preserve environment variables in convex deploy

Changed from 'cd ../web && bun run build' to 'bun --cwd ../web run build'
to prevent environment variable loss when changing directories within
the --cmd subshell.

When using `cd` within convex deploy --cmd, the NEXT_PUBLIC_CONVEX_URL
environment variable set by Convex doesn't properly propagate to the
subshell, causing "NEXT_PUBLIC_CONVEX_URL is not configured" errors.

Using --cwd keeps the command in the same shell, preserving env vars.

Fixes: Error: NEXT_PUBLIC_CONVEX_URL is not configured in preview deployments

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: leoisadev8

apps/server/package.json

@@ -4,7 +4,7 @@
   "type": "module",
   "scripts": {
     "dev": "convex dev",
-    "build": "if [ \"$NEXT_PUBLIC_DEPLOYMENT\" = \"preview\" ]; then convex deploy --cmd-url-env-var-name NEXT_PUBLIC_CONVEX_URL --cmd 'cd ../web && bun run build' --preview-run previewSeed --preview-create NEXT_PUBLIC_DEPLOYMENT=preview NEXT_PUBLIC_APP_URL=https://$VERCEL_URL; else convex deploy --cmd-url-env-var-name NEXT_PUBLIC_CONVEX_URL --cmd 'cd ../web && bun run build'; fi",
+    "build": "if [ \"$NEXT_PUBLIC_DEPLOYMENT\" = \"preview\" ]; then convex deploy --cmd-url-env-var-name NEXT_PUBLIC_CONVEX_URL --cmd 'bun --cwd ../web run build' --preview-run previewSeed --preview-create NEXT_PUBLIC_DEPLOYMENT=preview NEXT_PUBLIC_APP_URL=https://$VERCEL_URL; else convex deploy --cmd-url-env-var-name NEXT_PUBLIC_CONVEX_URL --cmd 'bun --cwd ../web run build'; fi",
     "check-types": "tsc --noEmit || true",
     "test": "echo \"No Convex tests yet\""
   },