Lift drill into evals/ at 013fcb8b7dbefd6d3fa4653493e5d2ec8e7f985b

rsync of obra/drill@013fcb8b7d into superpowers/evals/, excluding
.git/, .venv/, results/, .env/, __pycache__/, *.egg-info/,
.private-journal/.

The drill repo is unaffected by this commit; archival is a separate
manual step after this PR merges.

Source SHA recorded at evals/.drill-source-sha for divergence
detection.

evals/tests/test_backend.py

@@ -0,0 +1,145 @@
+from pathlib import Path
+
+import pytest
+
+from drill.backend import Backend, load_backend
+
+
+@pytest.fixture
+def backends_dir():
+    return Path(__file__).parent.parent / "backends"
+
+
+class TestLoadBackend:
+    def test_loads_claude_backend(self, backends_dir):
+        backend = load_backend("claude", backends_dir)
+        assert backend.name == "claude"
+        assert backend.cli == "claude"
+        assert "--dangerously-skip-permissions" in backend.args
+
+    def test_loads_codex_backend(self, backends_dir):
+        backend = load_backend("codex", backends_dir)
+        assert backend.name == "codex"
+        assert backend.cli == "codex"
+
+    def test_unknown_backend_raises(self, backends_dir):
+        with pytest.raises(FileNotFoundError):
+            load_backend("nonexistent", backends_dir)
+
+    def test_loads_claude_opus_4_6_variant(self, backends_dir, monkeypatch):
+        monkeypatch.setenv("SUPERPOWERS_ROOT", "/tmp/sp")
+        backend = load_backend("claude-opus-4-6", backends_dir)
+        assert backend.name == "claude-opus-4-6"
+        assert backend.family == "claude"
+        assert backend.model == "claude-opus-4-6"
+
+
+class TestBackendBuildCommand:
+    def test_claude_build_command(self, backends_dir, monkeypatch):
+        monkeypatch.setenv("SUPERPOWERS_ROOT", "/tmp/superpowers")
+        backend = load_backend("claude", backends_dir)
+        cmd = backend.build_command("/tmp/workdir")
+        assert cmd[0] == "claude"
+        assert "--plugin-dir" in cmd
+        assert "/tmp/superpowers" in cmd
+
+    def test_codex_build_command(self, backends_dir, monkeypatch):
+        monkeypatch.setenv("SUPERPOWERS_ROOT", "/tmp/superpowers")
+        backend = load_backend("codex", backends_dir)
+        cmd = backend.build_command("/tmp/workdir")
+        assert cmd[0] == "codex"
+
+
+class TestBackendEnvValidation:
+    def test_missing_env_raises(self, backends_dir, monkeypatch):
+        monkeypatch.delenv("ANTHROPIC_API_KEY", raising=False)
+        monkeypatch.delenv("SUPERPOWERS_ROOT", raising=False)
+        backend = load_backend("claude", backends_dir)
+        with pytest.raises(EnvironmentError, match="ANTHROPIC_API_KEY"):
+            backend.validate_env()
+
+
+class TestBackendIdleDetection:
+    def test_ready_pattern_matches(self, backends_dir):
+        backend = load_backend("claude", backends_dir)
+        assert backend.is_ready_line("❯ ")
+        assert backend.is_ready_line("Human: ")
+        assert not backend.is_ready_line("Running tool...")
+
+
+class TestBackendModelExtraction:
+    def test_extract_model_from_args(self, backends_dir, monkeypatch):
+        monkeypatch.setenv("SUPERPOWERS_ROOT", "/tmp/sp")
+        backend = load_backend("claude", backends_dir)
+        assert backend.model == "opus"
+
+    def test_no_model_flag_returns_none(self):
+        backend = Backend(
+            name="test",
+            cli="test",
+            args=["--foo", "bar"],
+            required_env=[],
+            hooks={"pre_run": [], "post_run": []},
+            shutdown="/exit",
+            idle={},
+            startup_timeout=30,
+            terminal={},
+            session_logs={},
+        )
+        assert backend.model is None
+
+    def test_extracts_from_short_m_flag(self):
+        backend = Backend(
+            name="test",
+            cli="test",
+            args=["-m", "gemini-2.5-flash"],
+            required_env=[],
+            hooks={"pre_run": [], "post_run": []},
+            shutdown="/exit",
+            idle={},
+            startup_timeout=30,
+            terminal={},
+            session_logs={},
+        )
+        assert backend.model == "gemini-2.5-flash"
+
+
+class TestBackendFamily:
+    def test_claude_backend_family(self, backends_dir, monkeypatch):
+        monkeypatch.setenv("SUPERPOWERS_ROOT", "/tmp/sp")
+        backend = load_backend("claude", backends_dir)
+        assert backend.family == "claude"
+
+    def test_codex_backend_family(self, backends_dir):
+        backend = load_backend("codex", backends_dir)
+        assert backend.family == "codex"
+
+    def test_variant_name_preserves_family(self):
+        backend = Backend(
+            name="claude-opus-4-6",
+            cli="claude",
+            args=[],
+            required_env=[],
+            hooks={"pre_run": [], "post_run": []},
+            shutdown="/exit",
+            idle={},
+            startup_timeout=30,
+            terminal={},
+            session_logs={},
+        )
+        assert backend.family == "claude"
+
+    def test_unknown_family_is_other(self):
+        backend = Backend(
+            name="random-xyz",
+            cli="xyz",
+            args=[],
+            required_env=[],
+            hooks={"pre_run": [], "post_run": []},
+            shutdown="/exit",
+            idle={},
+            startup_timeout=30,
+            terminal={},
+            session_logs={},
+        )
+        assert backend.family == "other"