chore: add lsp:config script for SourceKit-LSP via xcode-build-server

Generates buildServer.json at the repo root so SourceKit-LSP can resolve
symbols in both ios/ library sources and the example app via a single config.

Author: mgcrea

.gitignore

@@ -16,4 +16,6 @@ link-assets-manifest.json
 
 AGENTS.md
 CLAUDE.md
-.claude/
+.claude/
+
+buildServer.json

package.json

@@ -64,4 +64,4 @@
     "node": ">=18"
   },
   "packageManager": "pnpm@10.33.2"
-}
+}