fix(dashboard): handle missing OpenClaw CLI during dispatch

[luoyanglang]

Summary

Issue: #289 — 自动派发异常: [WinError 2] 系统找不到指定的文件
Type: Bug Fix
Severity: Medium

This PR makes dashboard auto-dispatch handle a missing OpenClaw CLI explicitly. Instead of surfacing a raw Windows [WinError 2] message to users, the scheduler now records an actionable openclaw-missing status and explains how to fix PATH / OPENCLAW_BIN.

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Root Cause

dashboard/server.py::dispatch_for_state() builds the auto-dispatch command with a hardcoded executable name:

cmd = ['openclaw', 'agent', '--agent', agent_id, '-m', msg, '--timeout', '300']
result = subprocess.run(cmd, capture_output=True, text=True, timeout=310)

On Windows, if openclaw is not on PATH, or if the npm-installed CLI is exposed through an openclaw.cmd shim that is not resolved, subprocess.run() raises FileNotFoundError / [WinError 2]. The old dashboard path only caught the generic Exception, so the task scheduler displayed a non-actionable dispatch error.

This is different from OpenClaw runtime failures: the process never starts.

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Fix Description

Changed files:

• dashboard/server.py — add _resolve_openclaw_bin() using OPENCLAW_BIN or shutil.which('openclaw')
• dashboard/server.py — preflight the CLI before dispatching, recording lastDispatchStatus = openclaw-missing if it is unavailable
• dashboard/server.py — add a dedicated FileNotFoundError fallback for invalid configured paths
• tests/test_dashboard_dispatch.py — add a regression test for the missing CLI path

Rationale:

• shutil.which() resolves Windows npm .cmd shims more reliably than passing a bare command name directly
• OPENCLAW_BIN gives Windows users a direct escape hatch if their shell PATH differs from the dashboard process PATH
• The fix is scoped to dashboard auto-dispatch error handling and does not change the state machine or OpenClaw command arguments

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Test Results

Test	Description	Status
pytest tests/test_dashboard_dispatch.py tests/test_server.py	Covers missing OpenClaw CLI dispatch path plus existing server health route	✅ PASS
python -m py_compile dashboard/server.py tests/test_dashboard_dispatch.py	Syntax check for changed Python files	✅ PASS
git diff --check	Whitespace / patch formatting check	✅ PASS

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Disprove Analysis

是否已有其他地方修复

edict/backend/app/workers/dispatch_worker.py already catches FileNotFoundError and reports openclaw command not found, but the stdlib dashboard server still had its own legacy auto-dispatch path without the same protection. #289 maps to the dashboard scheduler message, so that path still needed a fix.

影响范围

This only affects dashboard auto-dispatch when the OpenClaw CLI cannot be resolved or launched. Successful dispatch still uses the same command shape:

openclaw agent --agent <agent_id> -m <message> --timeout 300

边界情况

• If openclaw is available on PATH, dispatch proceeds as before.
• If Windows exposes openclaw.cmd, shutil.which('openclaw') can resolve it.
• If users need a custom path, they can set OPENCLAW_BIN.
• If OPENCLAW_BIN points to a bad path, FileNotFoundError is still converted to openclaw-missing.

已知局限

This does not install OpenClaw automatically. It only turns a raw [WinError 2] into an actionable dashboard error so users can fix their CLI/PATH setup.

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Checklist

• 代码遵循项目现有风格
• 相关 issue 编号在 PR 描述中已引用
• 有测试覆盖
• 无硬编码路径、密钥、调试输出

Found during issue triage. Happy to adjust the status wording if you prefer a different dashboard label.