add baseline safety net testing

Author: rcholic

.github/workflows/test.yml

@@ -373,6 +373,15 @@ jobs:
             print('WARNING: Could not find assert_ method call in assert_done')
             sys.exit(1)
         PYEOF
+
+    - name: Phase 0 regression safety net (unit)
+      shell: bash
+      run: |
+        pytest tests/unit/test_agent_runtime_phase0.py -v
+
+    - name: Run full test suite
+      shell: bash
+      run: |
         pytest tests/ -v
       env:
         CI: true

tests/unit/test_agent_runtime_phase0.py

@@ -0,0 +1,81 @@
+from __future__ import annotations
+
+from unittest.mock import MagicMock
+
+from sentience.agent_runtime import AgentRuntime
+from sentience.models import BBox, Element, VisualCues
+from sentience.verification import is_disabled, is_enabled, value_equals
+
+
+class MockBackend:
+    """Mock BrowserBackend implementation for unit tests."""
+
+    async def get_url(self) -> str:
+        return "https://example.com"
+
+    async def refresh_page_info(self):
+        return None
+
+
+class MockTracer:
+    """Mock Tracer for unit tests."""
+
+    def __init__(self) -> None:
+        self.events: list[dict] = []
+
+    def emit(self, event_type: str, data: dict, step_id: str | None = None) -> None:
+        self.events.append(
+            {
+                "type": event_type,
+                "data": data,
+                "step_id": step_id,
+            }
+        )
+
+
+def test_assert_state_predicates_use_snapshot_context() -> None:
+    """State-aware predicates should run against snapshot context."""
+    backend = MockBackend()
+    tracer = MockTracer()
+    runtime = AgentRuntime(backend=backend, tracer=tracer)
+    runtime.begin_step(goal="Test")
+
+    cues = VisualCues(is_primary=False, background_color_name=None, is_clickable=True)
+    elements = [
+        Element(
+            id=1,
+            role="button",
+            text="Submit",
+            importance=10,
+            bbox=BBox(x=0, y=0, width=100, height=40),
+            visual_cues=cues,
+            disabled=False,
+        ),
+        Element(
+            id=2,
+            role="textbox",
+            text=None,
+            importance=5,
+            bbox=BBox(x=0, y=50, width=200, height=40),
+            visual_cues=cues,
+            value="hello",
+            input_type="text",
+            disabled=False,
+        ),
+        Element(
+            id=3,
+            role="button",
+            text="Disabled",
+            importance=4,
+            bbox=BBox(x=0, y=100, width=120, height=40),
+            visual_cues=cues,
+            disabled=True,
+        ),
+    ]
+
+    runtime.last_snapshot = MagicMock(url="https://example.com", elements=elements)
+
+    assert runtime.assert_(is_enabled("text~'Submit'"), label="enabled") is True
+    assert runtime.assert_(is_disabled("text~'Disabled'"), label="disabled") is True
+    assert runtime.assert_(value_equals("role=textbox", "hello"), label="value") is True
+    assert len(runtime._assertions_this_step) == 3