[feat]. Add @codex -h help summary command

tests/test_dispatcher.py

@@ -146,3 +146,43 @@ def test_process_one_job_skips_review_when_repo_config_disabled(monkeypatch) ->
     with session_factory() as session:
         stored_job = session.execute(select(ReviewJob).where(ReviewJob.id == job.id)).scalar_one()
         assert stored_job.status.value == "skipped"
+
+
+def test_process_one_job_help_command_posts_summary(monkeypatch) -> None:
+    posted_comments: list[str] = []
+    session_factory = get_session_factory()
+    with session_factory() as session:
+        enqueue_job(
+            session,
+            repo="acme/repo",
+            pr_number=12,
+            head_sha="abc12345",
+            trigger_comment_id=114,
+            trigger_comment_body="@codex -h",
+            requested_by="alice",
+            command=ParsedCommand(name="help", raw="@codex -h"),
+        )
+
+    class _FakeGiteaClient:
+        def __init__(self, _settings) -> None:
+            pass
+
+        def list_issue_comments(self, _repo: str, _pr_number: int):
+            return [
+                {"body": "Please check auth edge cases", "user": {"username": "alice"}},
+                {"body": "On it, running review now.", "user": {"username": "codex-bot"}},
+            ]
+
+        def post_issue_comment(self, _repo: str, _pr_number: int, body: str) -> int:
+            posted_comments.append(body)
+            return 903
+
+    monkeypatch.setattr("gitea_codex_bot.workers.dispatcher.GiteaClient", _FakeGiteaClient)
+
+    assert process_one_job(get_settings()) is True
+    assert posted_comments
+    body = posted_comments[0]
+    assert "## Codex Help" in body
+    assert "@codex -h" in body
+    assert "Discussion summary" in body
+    assert "@alice: Please check auth edge cases" in body