feat: rebuild work queue api with fastapi and postgres

tests/test_api.py

@@ -0,0 +1,47 @@
+from datetime import datetime, UTC
+from uuid import uuid4
+
+import pytest
+
+from app.db import validate_transition
+from app.models import Project, WorkItem
+
+
+def test_validate_transition_rules():
+    validate_transition("queued", "dispatched", "steve-w", None, None)
+    validate_transition("in_progress", "completed", "steve-w", "success", "done")
+    with pytest.raises(Exception):
+        validate_transition("queued", "dispatched", None, None, None)
+    with pytest.raises(Exception):
+        validate_transition("in_progress", "blocked", "steve-w", None, None)
+
+
+def test_models_shape():
+    now = datetime.now(UTC).replace(microsecond=0)
+    project = Project(
+        id=uuid4(),
+        name="Queue",
+        external_ref=None,
+        created_at=now,
+        updated_at=now,
+    )
+    work = WorkItem(
+        id=uuid4(),
+        project_id=project.id,
+        type="code_review",
+        description="Review PR",
+        payload={"pr": 3},
+        priority=2,
+        status="queued",
+        assigned_agent="steve-w",
+        created_by="marcus-a",
+        created_at=now,
+        updated_at=now,
+        completed_at=None,
+        outcome=None,
+        notes=None,
+        dispatch_log=[],
+    )
+    assert project.name == "Queue"
+    assert work.priority == 2
+    assert work.payload == {"pr": 3}