feat(grok-cli): render config.toml + map per-role grok CLI flags

First piece of the Grok CLI provider that replaces the opencode runtime: a
pure, unit-tested module the agent entrypoint runs to translate the mounted
mcp-config.json into ~/.grok/config.toml ([mcp_servers]) and compute the
per-role 'grok -p' flags — subagent/shell/edit tool removal, raw-git-mutation
and rm-rf denies, reasoning effort — mirroring ClaudeCodeProvider's per-role
permissions with native grok flags instead of an opencode permission block +
JS guard plugins. Uses tomli_w. The rendered config + env injection are
validated live against grok-build (the model called the server through it).

tests/unit/llm/providers/test_grok_cli_config.py

@@ -0,0 +1,94 @@
+"""grok_cli_config — mcp-config → config.toml + per-role grok CLI flags."""
+
+from __future__ import annotations
+
+import tomllib
+from typing import TYPE_CHECKING
+
+from roboco.llm.providers import grok_cli_config as gc
+
+if TYPE_CHECKING:
+    import pytest
+
+_SAMPLE_MCP = {
+    "mcpServers": {
+        "roboco-flow": {
+            "command": "uv",
+            "args": ["run", "--no-sync", "python", "-m", "roboco.mcp.flow_server"],
+            "env": {"ROBOCO_AGENT_ID": "be-dev-1", "ROBOCO_AGENT_TOKEN": "tok-123"},
+        },
+        "roboco-do": {"command": "uv", "args": ["run", "x"]},
+    }
+}
+
+
+def _disallowed(args: list[str]) -> str:
+    return args[args.index("--disallowed-tools") + 1]
+
+
+def test_render_config_toml_is_valid_toml_and_injects_env() -> None:
+    parsed = tomllib.loads(gc.render_config_toml(_SAMPLE_MCP))
+    flow = parsed["mcp_servers"]["roboco-flow"]
+    assert flow["command"] == "uv"
+    assert flow["args"][:2] == ["run", "--no-sync"]
+    # The gateway env (token) reaches the server block — the keystone.
+    assert flow["env"]["ROBOCO_AGENT_TOKEN"] == "tok-123"
+    # A server with no env omits the key entirely.
+    assert "env" not in parsed["mcp_servers"]["roboco-do"]
+
+
+def test_render_config_toml_empty_when_no_servers() -> None:
+    assert gc.render_config_toml({}) == ""
+    assert gc.render_config_toml({"mcpServers": {}}) == ""
+
+
+def test_developer_flags(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.delenv("ROBOCO_GROK_REASONING_EFFORT", raising=False)
+    args = gc.grok_cli_args("be-dev-1")
+    dis = _disallowed(args)
+    # Developer writes code + runs a shell → only subagents removed.
+    assert "Agent" in dis
+    assert "run_terminal_cmd" not in dis
+    assert "search_replace" not in dis
+    # Raw git mutation + destructive ops denied even with a shell.
+    assert "--deny" in args
+    assert "Bash(git push*)" in args
+    assert "Bash(rm -rf*)" in args
+    # Code-quality role keeps full reasoning.
+    assert "--effort" not in args
+
+
+def test_pr_reviewer_flags(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.delenv("ROBOCO_GROK_REASONING_EFFORT", raising=False)
+    args = gc.grok_cli_args("pr-reviewer-1")
+    dis = _disallowed(args)
+    assert "run_terminal_cmd" in dis  # read-only reviewer: no shell
+    assert "search_replace" in dis  # no editing
+    assert "--deny" not in args  # bash removed → no command rules left
+    assert "--effort" not in args  # code-quality reviewer keeps full reasoning
+
+
+def test_main_pm_keeps_shell_but_denies_git(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.delenv("ROBOCO_GROK_REASONING_EFFORT", raising=False)
+    args = gc.grok_cli_args("main-pm")
+    dis = _disallowed(args)
+    assert "run_terminal_cmd" not in dis  # PM keeps a shell
+    assert "search_replace" in dis  # but does not write code
+    assert "Bash(git push*)" in args  # raw git mutation denied
+    assert args[args.index("--effort") + 1] == "low"
+
+
+def test_effort_override(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("ROBOCO_GROK_REASONING_EFFORT", "high")
+    assert (
+        gc.grok_cli_args("be-dev-1")[gc.grok_cli_args("be-dev-1").index("--effort") + 1]
+        == "high"
+    )
+    # "full" disables the per-role reduction entirely.
+    monkeypatch.setenv("ROBOCO_GROK_REASONING_EFFORT", "full")
+    assert "--effort" not in gc.grok_cli_args("main-pm")
+
+
+def test_max_turns_is_emitted() -> None:
+    args = gc.grok_cli_args("be-dev-1", max_turns=7)
+    assert args[args.index("--max-turns") + 1] == "7"