fix(01-03): exclude foundry-pf2e clone from build tsconfig

The Foundry pf2e dev clone under prisma/data/foundry-pf2e was already excluded from tsconfig.json (d421aad), but nest start --watch and nest build use tsconfig.build.json, which overrides exclude and globs the whole project. With the clone present this pulled ~39k .ts files into compilation (10,716 errors) and prevented the backend dev server from starting. Mirror the exclude in the build config.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

server/tsconfig.build.json

@@ -1,4 +1,4 @@
 {
   "extends": "./tsconfig.json",
-  "exclude": ["node_modules", "test", "dist", "**/*spec.ts"]
+  "exclude": ["node_modules", "test", "dist", "**/*spec.ts", "prisma/data/foundry-pf2e"]
 }