ci(runner): retire descriptor launch probe

.github/workflows/runner-full-stack-e2e.yml

@@ -347,63 +347,6 @@ jobs:
         if: matrix.environmentId == 'local' && (matrix.profileId == 'runner-opencode' || startsWith(matrix.profileId, 'runner-acpx-'))
         run: pnpm --filter @paperclipai/paperclip-runner build:typescript
 
-      - name: Diagnose descriptor-safe ACPX bundle
-        if: matrix.environmentId == 'local' && startsWith(matrix.profileId, 'runner-acpx-')
-        run: |
-          python3 <<'PY'
-          import json
-          import os
-          import shutil
-          import subprocess
-          import sys
-
-          def snapshot(path):
-              descriptor = os.memfd_create("paperclip-verified-launch")
-              with open(path, "rb") as source:
-                  while chunk := source.read(64 * 1024):
-                      os.write(descriptor, chunk)
-              os.lseek(descriptor, 0, os.SEEK_SET)
-              os.fchmod(descriptor, 0o500)
-              return descriptor
-
-          node_descriptor = snapshot(shutil.which("node"))
-          sidecar_descriptor = snapshot(
-              "packages/paperclip-runner/dist/cli/acpx-runtime-sidecar.cjs"
-          )
-          environment = os.environ.copy()
-          environment["PAPERCLIP_ACPX_PROVIDER_PACKAGE_ROOT"] = os.path.abspath(
-              "packages/paperclip-runner"
-          )
-          request = {
-              "protocolVersion": 2,
-              "id": 1,
-              "command": "initialize",
-              "params": {"agent": "codex", "model": "gpt-5.6-sol"},
-          }
-          loader = r'''const fs=require("node:fs");const Module=require("node:module");const filename=process.argv[1];const source=fs.readFileSync(filename,"utf8").replace(/^#![^\r\n]*(?:\r?\n|$)/,"");const artifact=new Module(filename);artifact.filename=filename;artifact.paths=[];artifact._compile(source,filename);'''
-          result = subprocess.run(
-              [
-                  f"/proc/self/fd/{node_descriptor}",
-                  "--eval",
-                  loader,
-                  f"/proc/self/fd/{sidecar_descriptor}",
-              ],
-              input=json.dumps(request) + "\n",
-              text=True,
-              capture_output=True,
-              timeout=15,
-              pass_fds=(node_descriptor, sidecar_descriptor),
-              env=environment,
-          )
-          sys.stdout.write(result.stdout)
-          sys.stderr.write(result.stderr)
-          if result.returncode != 0:
-              raise SystemExit(result.returncode)
-          response = json.loads(result.stdout.strip().splitlines()[0])
-          if response.get("ok") is not True:
-              raise SystemExit("descriptor-safe ACPX initialize failed")
-          PY
-
       - name: Qualify local provider Node interpreter
         if: matrix.environmentId == 'local' && (matrix.profileId == 'runner-opencode' || startsWith(matrix.profileId, 'runner-acpx-'))
         run: |