fix(graph): resolve instrument identity to stop wrong-company hallucination

Agents had no ground-truth ticker→company mapping, so the market analyst
could pattern-match a price chart to the wrong company (e.g. TOTDY read as
"TotalEnergies"), and every downstream agent inherited the bad framing.

Resolve identity once at run start via a cached, fail-open yfinance lookup
and inject company/sector/exchange into the shared instrument context that
all twelve agents consume, with an explicit do-not-substitute instruction.
Resolution runs on both the propagate() and CLI entry points.

Also replaces the bare "Continue" message-clear placeholder, which some
OpenAI-compatible providers interpreted as the user task, with a
context-anchored placeholder carrying the resolved identity and date.

#814 #888

tradingagents/agents/managers/research_manager.py

@@ -4,7 +4,7 @@ from __future__ import annotations
 
 from tradingagents.agents.schemas import ResearchPlan, render_research_plan
 from tradingagents.agents.utils.agent_utils import (
-    build_instrument_context,
+    get_instrument_context_from_state,
     get_language_instruction,
 )
 from tradingagents.agents.utils.structured import (
@@ -17,7 +17,7 @@ def create_research_manager(llm):
     structured_llm = bind_structured(llm, ResearchPlan, "Research Manager")
 
     def research_manager_node(state) -> dict:
-        instrument_context = build_instrument_context(state["company_of_interest"])
+        instrument_context = get_instrument_context_from_state(state)
         history = state["investment_debate_state"].get("history", "")
 
         investment_debate_state = state["investment_debate_state"]