feat(agents): tarot agent — daily three-card draw (situation/action/outcome) (#120)

Draws 3 Major Arcana cards from a daily seed (user_id + date) so the
reading is stable within a day and unique per user. Card meanings and
action hints are precomputed in the agent; the orchestrator receives a
structured prompt snippet and is instructed to weave the themes into a
grounded, practical tip without explaining the cards.

No inferred params, no external data — requires only data:core consent.
TTL 6 h (refreshes at most twice daily).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ml/agents/tests/test_agents.py

@@ -13,6 +13,7 @@ from ml.agents.momentum import MomentumAgent
 from ml.agents.time_of_day import TimeOfDayAgent
 from ml.agents.recent_patterns import RecentPatternsAgent
 from ml.agents.focus_area import FocusAreaAgent
+from ml.agents.tarot import TarotAgent, _daily_draw, _CARDS, _POSITIONS
 from ml.agents.registry import get_agent, all_agents
 
 _NOW = datetime(2026, 5, 1, 9, 0, 0, tzinfo=timezone.utc)  # Thursday 09:00 UTC
@@ -250,13 +251,59 @@ class TestFocusAreaAgent:
         assert all("label" in c and "task_count" in c and "tasks" in c for c in clusters)
 
 
+# ── TarotAgent ────────────────────────────────────────────────────────────────
+
+class TestTarotAgent:
+    agent = TarotAgent()
+
+    def test_basic_output(self):
+        out = self.agent.compute(_inp())
+        _check_output(out, self.agent)
+        assert "situation" in out.prompt_text.lower()
+        assert "action" in out.prompt_text.lower()
+        assert "outcome" in out.prompt_text.lower()
+        assert out.signals_snapshot["date"] == "2026-05-01"
+        assert len(out.signals_snapshot["reading"]) == 3
+
+    def test_three_distinct_cards(self):
+        out = self.agent.compute(_inp())
+        cards = [r["card"] for r in out.signals_snapshot["reading"]]
+        assert len(set(cards)) == 3
+
+    def test_positions_labelled(self):
+        out = self.agent.compute(_inp())
+        positions = [r["position"] for r in out.signals_snapshot["reading"]]
+        assert positions == list(_POSITIONS)
+
+    def test_daily_stability(self):
+        out1 = self.agent.compute(_inp(now=datetime(2026, 5, 1, 8, 0, 0, tzinfo=timezone.utc)))
+        out2 = self.agent.compute(_inp(now=datetime(2026, 5, 1, 20, 0, 0, tzinfo=timezone.utc)))
+        assert out1.signals_snapshot["reading"] == out2.signals_snapshot["reading"]
+
+    def test_different_days_different_draw(self):
+        out1 = self.agent.compute(_inp(now=datetime(2026, 5, 1, 9, 0, 0, tzinfo=timezone.utc)))
+        out2 = self.agent.compute(_inp(now=datetime(2026, 5, 2, 9, 0, 0, tzinfo=timezone.utc)))
+        assert out1.signals_snapshot["reading"] != out2.signals_snapshot["reading"]
+
+    def test_different_users_different_draw(self):
+        out1 = self.agent.compute(_inp(user_id="user-A"))
+        out2 = self.agent.compute(_inp(user_id="user-B"))
+        assert out1.signals_snapshot["reading"] != out2.signals_snapshot["reading"]
+
+    def test_daily_draw_returns_valid_indices(self):
+        indices = _daily_draw("u1", "2026-05-01")
+        assert len(indices) == 3
+        assert len(set(indices)) == 3
+        assert all(0 <= i < len(_CARDS) for i in indices)
+
+
 # ── Registry ─────────────────────────────────────────────────────────────────
 
 class TestRegistry:
     def test_all_agents_present(self):
         agents = all_agents()
         ids = {a.agent_id for a in agents}
-        assert ids == {"overdue-task", "momentum", "time-of-day", "recent-patterns", "focus-area", "health-vitals"}
+        assert ids == {"overdue-task", "momentum", "time-of-day", "recent-patterns", "focus-area", "health-vitals", "tarot"}
 
     def test_get_agent(self):
         a = get_agent("momentum")