refactor: replace BunProc with Npm module using @npmcli/arborist (#18308)

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>
Co-authored-by: Brendan Allan <git@brendonovich.dev>
Co-authored-by: Aiden Cline <aidenpcline@gmail.com>

packages/opencode/package.json

@@ -53,6 +53,7 @@
     "@types/bun": "catalog:",
     "@types/cross-spawn": "6.0.6",
     "@types/mime-types": "3.0.1",
+    "@types/npmcli__arborist": "6.3.3",
     "@types/semver": "^7.5.8",
     "@types/turndown": "5.0.5",
     "@types/which": "3.0.4",
@@ -94,6 +95,7 @@
     "@hono/standard-validator": "0.1.5",
     "@hono/zod-validator": "catalog:",
     "@modelcontextprotocol/sdk": "1.27.1",
+    "@npmcli/arborist": "9.4.0",
     "@octokit/graphql": "9.0.2",
     "@octokit/rest": "catalog:",
     "@openauthjs/openauth": "catalog:",