Add Consensus Tool for Multi-Model Perspective Gathering (#67)

* WIP
Refactor resolving mode_names, should be done once at MCP call boundary
Pass around model context instead
Consensus tool allows one to get a consensus from multiple models, optionally assigning one a 'for' or 'against' stance to find nuanced responses.

* Deduplication of model resolution, model_context should be available before reaching deeper parts of the code
Improved abstraction when building conversations
Throw programmer errors early

* Guardrails
Support for `model:option` format at MCP boundary so future tools can use additional options if needed instead of handling this only for consensus
Model name now supports an optional ":option" for future use

* Simplified async flow

* Improved model for request to support natural language
Simplified async flow

* Improved model for request to support natural language
Simplified async flow

* Fix consensus tool async/sync patterns to match codebase standards

CRITICAL FIXES:
- Converted _get_consensus_responses from async to sync (matches other tools)
- Converted store_conversation_turn from async to sync (add_turn is synchronous)
- Removed unnecessary asyncio imports and sleep calls
- Fixed ClosedResourceError in MCP protocol during long consensus operations

PATTERN ALIGNMENT:
- Consensus tool now follows same sync patterns as all other tools
- Only execute() and prepare_prompt() are async (base class requirement)
- All internal operations are synchronous like analyze, chat, debug, etc.

TESTING:
- MCP simulation test now passes: consensus_stance ✅
- Two-model consensus works correctly in ~35 seconds
- Unknown stance handling defaults to neutral with warnings
- All 9 unit tests pass (100% success rate)

The consensus tool async patterns were anomalous in the codebase.
This fix aligns it with the established synchronous patterns used
by all other tools while maintaining full functionality.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

* Fixed call order and added new test

* Cleanup dead comments
Docs for the new tool
Improved tests

---------

Co-authored-by: Claude <noreply@anthropic.com>

simulator_tests/__init__.py

@@ -7,6 +7,9 @@ Each test is in its own file for better organization and maintainability.
 
 from .base_test import BaseSimulatorTest
 from .test_basic_conversation import BasicConversationTest
+from .test_consensus_conversation import TestConsensusConversation
+from .test_consensus_stance import TestConsensusStance
+from .test_consensus_three_models import TestConsensusThreeModels
 from .test_content_validation import ContentValidationTest
 from .test_conversation_chain_validation import ConversationChainValidationTest
 from .test_cross_tool_comprehensive import CrossToolComprehensiveTest
@@ -48,6 +51,9 @@ TEST_REGISTRY = {
     "conversation_chain_validation": ConversationChainValidationTest,
     "vision_capability": VisionCapabilityTest,
     "xai_models": XAIModelsTest,
+    "consensus_conversation": TestConsensusConversation,
+    "consensus_stance": TestConsensusStance,
+    "consensus_three_models": TestConsensusThreeModels,
     # "o3_pro_expensive": O3ProExpensiveTest,  # COMMENTED OUT - too expensive to run by default
 }
 
@@ -73,5 +79,8 @@ __all__ = [
     "ConversationChainValidationTest",
     "VisionCapabilityTest",
     "XAIModelsTest",
+    "TestConsensusConversation",
+    "TestConsensusStance",
+    "TestConsensusThreeModels",
     "TEST_REGISTRY",
 ]