fix(gateway): stop terminal progress from posting the full command to messaging chats

#41215 rendered a terminal tool call as a native ```bash fenced block on
markdown platforms (Telegram, WhatsApp, Slack, and others), showing the full
command with no truncation, in both all/new and verbose modes. That posted
complete shell commands (heredocs, internal paths, destructive commands) into
the chat before the final answer, visible to everyone in it.

This restores the prior behavior: terminal progress shows the short, truncated
preview line that every other tool already uses, capped at tool_preview_length.
The supports_code_blocks capability flag is left in place for future use.
CLI/TUI rendering is a separate path and was unaffected.

Adds a regression test asserting terminal progress renders as a truncated
preview, not a fenced bash block, even on a markdown-capable gateway.

Fixes #41955

tests/gateway/test_run_progress_topics.py

@@ -1264,3 +1264,123 @@ async def test_verbose_mode_respects_explicit_tool_preview_length(monkeypatch, t
     assert VerboseAgent.LONG_CODE not in all_content
     # But should still contain the truncated portion with "..."
     assert "..." in all_content
+
+
+class CodeBlockProgressAdapter(ProgressCaptureAdapter):
+    """A markdown-capable progress adapter (declares supports_code_blocks)."""
+
+    supports_code_blocks = True
+
+
+class TerminalCommandAgent:
+    """Emits a terminal tool.started with a real, multi-line command arg."""
+
+    CMD = (
+        "set -euo pipefail\n"
+        "printf 'node: '; node --version\n"
+        "npm install -g hyperframes@latest"
+    )
+
+    def __init__(self, **kwargs):
+        self.tool_progress_callback = kwargs.get("tool_progress_callback")
+        self.tools = []
+
+    def run_conversation(self, message, conversation_history=None, task_id=None):
+        self.tool_progress_callback(
+            "tool.started", "terminal", self.CMD, {"command": self.CMD}
+        )
+        # Let the async progress task drain the queue and send before returning.
+        time.sleep(0.35)
+        return {"final_response": "done", "messages": [], "api_calls": 1}
+
+
+@pytest.mark.asyncio
+async def test_terminal_progress_is_truncated_preview_not_bash_block(monkeypatch, tmp_path):
+    """Regression for #41215: terminal progress must render as a short truncated
+    preview, never the full command in a fenced ```bash block, even on a
+    markdown-capable (supports_code_blocks) gateway."""
+    monkeypatch.setenv("HERMES_TOOL_PROGRESS_MODE", "all")
+
+    fake_dotenv = types.ModuleType("dotenv")
+    fake_dotenv.load_dotenv = lambda *args, **kwargs: None
+    monkeypatch.setitem(sys.modules, "dotenv", fake_dotenv)
+
+    fake_run_agent = types.ModuleType("run_agent")
+    fake_run_agent.AIAgent = TerminalCommandAgent
+    monkeypatch.setitem(sys.modules, "run_agent", fake_run_agent)
+    import tools.terminal_tool  # noqa: F401 - register terminal emoji
+
+    adapter = CodeBlockProgressAdapter(platform=Platform.TELEGRAM)
+    runner = _make_runner(adapter)
+    gateway_run = importlib.import_module("gateway.run")
+    monkeypatch.setattr(gateway_run, "_hermes_home", tmp_path)
+    monkeypatch.setattr(gateway_run, "_resolve_runtime_agent_kwargs", lambda: {"api_key": "***"})
+
+    source = SessionSource(
+        platform=Platform.TELEGRAM,
+        chat_id="12345",
+        chat_type="dm",
+        thread_id=None,
+    )
+
+    result = await runner._run_agent(
+        message="hello",
+        context_prompt="",
+        history=[],
+        source=source,
+        session_id="sess-terminal-no-bash-block",
+        session_key="agent:main:telegram:dm:12345",
+    )
+
+    assert result["final_response"] == "done"
+    all_content = " ".join(call["content"] for call in adapter.sent)
+    all_content += " ".join(call["content"] for call in adapter.edits)
+    # Compact truncated preview, not a fenced bash block.
+    assert "```bash" not in all_content
+    assert 'terminal: "' in all_content
+    # The full multi-line command body must not reach the chat.
+    assert "npm install -g hyperframes@latest" not in all_content
+
+
+@pytest.mark.asyncio
+async def test_terminal_progress_no_bash_block_in_verbose_mode(monkeypatch, tmp_path):
+    """#41215 also rendered the bash block in verbose mode. The revert removed it
+    from both branches, so verbose progress must not emit a fenced ```bash block
+    either (verbose still shows args by opt-in, just not as a code block)."""
+    monkeypatch.setenv("HERMES_TOOL_PROGRESS_MODE", "verbose")
+
+    fake_dotenv = types.ModuleType("dotenv")
+    fake_dotenv.load_dotenv = lambda *args, **kwargs: None
+    monkeypatch.setitem(sys.modules, "dotenv", fake_dotenv)
+
+    fake_run_agent = types.ModuleType("run_agent")
+    fake_run_agent.AIAgent = TerminalCommandAgent
+    monkeypatch.setitem(sys.modules, "run_agent", fake_run_agent)
+    import tools.terminal_tool  # noqa: F401 - register terminal emoji
+
+    adapter = CodeBlockProgressAdapter(platform=Platform.TELEGRAM)
+    runner = _make_runner(adapter)
+    gateway_run = importlib.import_module("gateway.run")
+    monkeypatch.setattr(gateway_run, "_hermes_home", tmp_path)
+    monkeypatch.setattr(gateway_run, "_resolve_runtime_agent_kwargs", lambda: {"api_key": "***"})
+
+    source = SessionSource(
+        platform=Platform.TELEGRAM,
+        chat_id="12345",
+        chat_type="dm",
+        thread_id=None,
+    )
+
+    result = await runner._run_agent(
+        message="hello",
+        context_prompt="",
+        history=[],
+        source=source,
+        session_id="sess-terminal-verbose-no-bash",
+        session_key="agent:main:telegram:dm:12345",
+    )
+
+    assert result["final_response"] == "done"
+    all_content = " ".join(call["content"] for call in adapter.sent)
+    all_content += " ".join(call["content"] for call in adapter.edits)
+    assert "```bash" not in all_content