fix(graph): integrate #487 + #567 — sentiment label, route, propagate asset_type

- analyst_execution.py: rename "Social Analyst" / "Msg Clear Social"
  to "Sentiment Analyst" / "Msg Clear Sentiment" to match v0.2.5.
- conditional_logic.should_continue_social returns the renamed route.
- TradingAgentsGraph.propagate accepts asset_type and threads through
  to Propagator.create_initial_state.
- Regression test on the Sentiment Analyst label.

Verified end-to-end (NVDA stock + BTC-USD crypto) on gpt-5.4-mini.

tests/test_analyst_execution.py

@@ -34,6 +34,17 @@ class AnalystExecutionPlanTests(unittest.TestCase):
             "Fundamentals Analyst",
         )
 
+    def test_social_key_displays_as_sentiment_analyst(self):
+        # The wire key stays "social" for saved-config back-compat, but the
+        # user-visible agent_node label must match the v0.2.5 rename so the
+        # wall-time summary and any future consumer of agent_node says
+        # "Sentiment Analyst" rather than the legacy "Social Analyst".
+        plan = build_analyst_execution_plan(["social"])
+        spec = plan.specs[0]
+        self.assertEqual(spec.key, "social")
+        self.assertEqual(spec.agent_node, "Sentiment Analyst")
+        self.assertEqual(spec.report_key, "sentiment_report")
+
 
 class AnalystWallTimeTrackerTests(unittest.TestCase):
     def test_records_wall_time_when_analyst_completes(self):