fix(agentmain): reject unknown CLI arguments (v3, re-roll onto current main)

[Kailigithub]

Summary

Reject unsupported command-line arguments before GenericAgent initializes. This makes mistyped launch modes such as --goal fail with argparse's non-zero error instead of falling through to the interactive path.

Problem

agentmain.py used parse_known_args() and silently ignored unknown flags. A typo like --goal (intended for a different launcher) was accepted without warning, causing the process to fall through to interactive mode and hang without dispatching any work — users reported "agent launched but did nothing."

Fix

Single-source change in agentmain.py: when _unknown (leftover from parse_known_args()) is non-empty AND --reflect is not active, call parser.error() to print usage and exit non-zero.

--reflect mode is exempted because reflect scripts receive the extra key/value pairs as parameters and need them forwarded (existing behavior preserved).

args, _unknown = parser.parse_known_args()
if _unknown and not args.reflect:
    # Reject unknown CLI flags unless we are in --reflect mode, where
    # extra key/value pairs are forwarded to the reflect script as parameters.
    # Without this guard, typos like `--goal` silently fall through to
    # interactive mode and the process looks alive without doing any work.
    parser.error(f"unrecognized arguments: {' '.join(_unknown)}")
_extra_args = dict(zip([k.lstrip('-') for k in _unknown[::2]], _unknown[1::2])) if _unknown else {}

Verification

• python3 -m py_compile agentmain.py — syntax OK
• Regression harness at /tmp/test_issue_566.py — 4 checks:
  • test_source_has_guard: confirms if _unknown and not args.reflect + parser.error are present.
  • test_unknown_arg_rejected: python3 agentmain.py --goal /tmp/foo.json exits with code 2 and the message unrecognized arguments: --goal /tmp/foo.json.
  • test_help_still_works: --help exits 0 without the new guard firing.
  • test_extra_args_dict_still_populated_for_reflect: the _extra_args dict assignment is untouched.
• Three-step dance (stash → test fails on main → pop → test passes with fix) confirms the test catches the regression.

Scope

• 1 file, +6/-0 lines
• Single argparse guard, no runtime logic change
• Closes Goal Hive can silently hang when launched with unsupported --goal argument #566

[Kailigithub]

Closing this PR — its underlying work has been covered by #742 (fix(cli): reject unsupported agentmain arguments), which targets the same agentmain.py + same root cause (parse_known_args() silently accepting unknown flags when --reflect is not active) with a stricter, more comprehensive approach:

• fix(agentmain): reject unknown CLI arguments (v3, re-roll onto current main) #703 v3: single parser.error() guard for any unknown flag when --reflect is not active (1 case, +6 lines)
• fix(cli): reject unsupported agentmain arguments #742: rejects unknown args when no --reflect + rejects empty reflect script path + enforces --name key format + rejects option-shaped missing values + strips exactly two key dashes (6 cases, +92 lines) + isolated subprocess regression harness

The fix is a strict superset of #703's behavior; #742 covers #703's case and adds deeper malformed-input guards. Diff preserved on the branch tip and can be cherry-picked at any time. Happy to reopen if the simpler one-line approach is preferred over the comprehensive guard.

---

Closing this PR — 同一文件同一 bug 域已在 #742（fix(cli): reject unsupported agentmain arguments）中以更严格、更全面的方式处理：

• fix(agentmain): reject unknown CLI arguments (v3, re-roll onto current main) #703 v3: 在 --reflect 未启用时，对任意未知 flag 调一次 parser.error()（1 个分支，+6 行）
• fix(cli): reject unsupported agentmain arguments #742: 拒绝无 --reflect 时的未知参数 + 拒绝空 reflect 脚本路径 + 校验 --name 键名格式 + 拒绝形如 --name --other 的 option-shaped 缺值 + 用 k[2:] 精确剥离两个 dash（6 个分支，+92 行）+ 独立子进程回归测试

修复效果是 #703 v3 的严格超集；#742 覆盖 #703 v3 的 case 并补充了更深的畸形输入守卫。差异保留在分支 tip 可随时 cherry-pick。如更倾向于单行简化写法，可重新打开本 PR。