feat: add proto codegen pipeline with buf and connect-es

- Add llm-multiverse repo as git submodule for proto files
- Configure buf with @bufbuild/protoc-gen-es for TypeScript codegen
- Generate typed Connect service stubs to src/lib/proto/
- Add `generate` npm script for proto regeneration
- Exclude generated proto files from ESLint

Closes #2

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -10,10 +10,16 @@
 		"prepare": "svelte-kit sync || echo ''",
 		"check": "svelte-kit sync && svelte-check --tsconfig ./tsconfig.json",
 		"check:watch": "svelte-kit sync && svelte-check --tsconfig ./tsconfig.json --watch",
+		"generate": "buf generate",
 		"lint": "eslint .",
 		"format": "prettier --write ."
 	},
 	"devDependencies": {
+		"@bufbuild/buf": "^1.66.1",
+		"@bufbuild/protobuf": "^2.11.0",
+		"@bufbuild/protoc-gen-es": "^2.11.0",
+		"@connectrpc/connect": "^2.1.1",
+		"@connectrpc/connect-web": "^2.1.1",
 		"@eslint/js": "^9.0.0",
 		"@sveltejs/adapter-auto": "^7.0.0",
 		"@sveltejs/kit": "^2.50.2",