refactor(protocol): extract server contracts (#33708)

packages/protocol/package.json

@@ -0,0 +1,22 @@
+{
+  "$schema": "https://json.schemastore.org/package.json",
+  "name": "@opencode-ai/protocol",
+  "private": true,
+  "type": "module",
+  "license": "MIT",
+  "exports": {
+    "./*": "./src/*.ts"
+  },
+  "scripts": {
+    "typecheck": "tsgo --noEmit"
+  },
+  "dependencies": {
+    "@opencode-ai/schema": "workspace:*",
+    "effect": "catalog:"
+  },
+  "devDependencies": {
+    "@tsconfig/bun": "catalog:",
+    "@types/bun": "catalog:",
+    "@typescript/native-preview": "catalog:"
+  }
+}