feat: add authenticated Devin CLI bridge for LLM inference

[udi741]

Summary

Add a local OpenAI-compatible sidecar (devin_bridge) that routes TradingAgents LLM inference through an authenticated Devin CLI installation.

This lets users run TradingAgents without configuring a direct LLM-provider API key for model inference — the authenticated Devin CLI provides model access.

Architecture

TradingAgents remains responsible for graph orchestration, agents, prompts, schemas, and tool execution. The bridge is a separate sidecar that only translates model requests and responses.

No TradingAgents agents, financial tools, or graph logic are modified.

TradingAgents CLI
→ TradingAgents LangGraph
→ existing openai_compatible provider
→ local devin_bridge sidecar
→ authenticated devin CLI
→ selected Devin model

Features

• Authenticated Devin CLI for model inference.

• Model selection:

  • no model flag → Devin CLI configured/default model;
  • --model <id> → one explicit model for both aliases;
  • --quick-model <id> / --deep-model <id> → independent overrides.

• Model discovery with python -m devin_bridge --list-models.

• Single and multiple tool calls using a strict TOOL_CALLS protocol.

• Structured outputs remain compatible with TradingAgents .with_structured_output(...).

• Raw FINAL response transport for long Markdown/free-form model output.

• Strict protocol validation for malformed or ambiguous responses.

• Loopback-only server by default.

• No new Python dependencies; the authenticated devin CLI is an external prerequisite.

Testing

• 137 offline bridge tests pass.
• 667 existing upstream tests pass unchanged, with one optional dependency skip.
• Ruff passes on all touched Python files.
• Built-wheel verification confirms devin_bridge is packaged correctly.
• python -m devin_bridge --help works from an isolated wheel installation.

Scope

Core TradingAgents agents, LangGraph orchestration, financial tools, and schemas remain unchanged.

The only non-bridge files modified are:

• pyproject.toml to include devin_bridge* in package discovery.
• README.md to document Devin CLI support.

Validated model

GLM-5.2 High (glm-5-2) was validated end-to-end with the complete TradingAgents workflow.

Other Devin models may work but were not validated as part of this contribution.