fix: unwrap app.call envelopes, clean up opencode diagnostics, and align test contracts

[andrewwhitecdw]

Summary

Fixes several runtime bugs where AgentField execution envelopes were not unwrapped before being used, cleans up noisy diagnostic logging in the OpenCode provider, and brings stale tests back in line with the current implementation.

Changes

• Runtime envelope unwrapping
  • "swe_af/fast/verifier.py": unwrap "app.call()" result before building "FastVerificationResult".
  • "swe_af/execution/dag_executor.py": unwrap replanner "call_fn()" result before constructing "ReplanDecision".
  • "swe_af/app.py": unwrap issue-writer results, external "execute_fn_target" returns, and "resume_build" output.
• Fast planner robustness
  • "swe_af/fast/planner.py": catch "Exception" (AgentField raises "AgentFieldClientError") in "_note()" so detached-router runs don't crash.
• OpenCode provider cleanup
  • "swe_af/agent_ai/providers/opencode/client.py": move logger below imports, add empty-file guard, and downgrade routine diagnostics from warning to debug.
• Config / dependencies
  • Re-comment placeholder "ZHIPU_API_KEY" in ".env.example".
  • Keep "ZHIPU_API_KEY" env wiring in "docker-compose.yml" and revert control-plane port to default 8080.
  • Align "requirements.txt" agentfield pin with "requirements-docker.txt" (>=0.1.41).
  • Add "pytest-asyncio" to "pyproject.toml" dev dependencies.
• Stale test updates
  • Update verifier forwarding tests to match the current "fast_verify" contract.
  • Fix node_id and docker-compose tests to use repo-relative paths and the correct default.
  • Allow intentional cross-cutting file changes in AC-14.

Verification

Note: run tests under Python 3.12/3.13 with "agentfield>=0.1.41". The workspace's existing ".venv" uses Python 3.14, which agentfield 0.1.41 does not yet support.

[andrewwhitecdw]

Closing in favor of the upstream PR Agent-Field#112.