fix(harness): stream Docker exec commands through stdin

[richuV]

Summary

• run Docker sandbox shell programs through docker exec -i ... sh -s
• keep shell text out of the host process argument list
• preserve UTF-8 complex commands and avoid Windows command-line length limits
• add unit contracts plus an opt-in real Docker regression test

Why

docker exec ... sh -c <command> puts the complete shell program in the Windows CreateProcess argument list. Complex nested quoting can be corrupted, and large filesystem scripts can exceed the host command-line limit.

The public Sandbox API and command semantics remain unchanged; only the Docker CLI transport changes.

Tests

• mvn -pl agentscope-harness spotless:check test -Dtest=DockerSandboxCommandTest,BaseSandboxFilesystemTest,HarnessAgentDistributedSandboxTest -Dsurefire.failIfNoSpecifiedTests=false
  • 16 tests, 12 passed, 4 environment-gated skipped
• AGENTSCOPE_DOCKER_INTEGRATION=true mvn -pl agentscope-harness test -Dtest=DockerSandboxCommandTest
  • 3/3 passed on Windows with Docker Desktop
  • covers nested quotes, $(dirname ...), paths with spaces, and a 100KB shell program
• downstream JCode acceptance against the patched 2.0.1-SNAPSHOT
  • real Docker provider lifecycle 1/1
  • Redis + Docker fresh-JVM writer 1/1
  • Redis + Docker fresh-JVM reader 1/1

Closes #2135.
Addresses #1560.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

---

u010143241 seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[codecov]

Codecov Report

❌ Patch coverage is 27.27273% with 8 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...rness/agent/sandbox/impl/docker/DockerSandbox.java	27.27%	8 Missing ⚠️

📢 Thoughts on this report? Let us know!

[AgentScopeJavaBot]

🤖 AI Review

Changes Docker sandbox command execution from sh -c to sh -s (stdin pipe), solving Windows command-line length limits, UTF-8 escaping issues, and process argument exposure. Well-scoped change (2 files, +108/-12) with comprehensive tests. Clean implementation, no issues found.