core: move npm service to core package for shared dependency management

packages/opencode/package.json

@@ -61,7 +61,6 @@
     "@types/cross-spawn": "catalog:",
     "@types/mime-types": "3.0.1",
     "@types/npm-package-arg": "6.1.4",
-    "@types/npmcli__arborist": "6.3.3",
     "@types/semver": "^7.5.8",
     "@types/turndown": "5.0.5",
     "@types/which": "3.0.4",
@@ -110,8 +109,6 @@
     "@hono/zod-validator": "catalog:",
     "@lydell/node-pty": "catalog:",
     "@modelcontextprotocol/sdk": "1.27.1",
-    "@npmcli/arborist": "9.4.0",
-    "@npmcli/config": "10.8.1",
     "@octokit/graphql": "9.0.2",
     "@octokit/rest": "catalog:",
     "@openauthjs/openauth": "catalog:",