feat: migrate multi-agent tools to sdk native patterns and model support (#143)

* feat: Major refactor - Migrate to Strands SDK native patterns & add comprehensive model support

🚀 Overview:
- Migrate custom implementations to native Strands SDK patterns
- Add comprehensive model provider support (9+ providers)
- Enhance reliability, performance, and user experience
- Maintain backward compatibility

🔄 Key Changes:
- agent_graph.py → graph.py (SDK GraphBuilder integration)
- use_llm.py → use_agent.py (enhanced nested agent creation)
- Complete swarm tool architecture overhaul
- Enhanced think tool with model switching
- Production-ready workflow orchestration
- New model utilities system in src/strands_tools/models/

📊 Impact:
- Files Changed: 25+ files
- Lines Added: ~2,000 lines
- Lines Removed: ~1,100 lines
- New model providers: Bedrock, Anthropic, LiteLLM, LlamaAPI, Ollama, OpenAI, Writer, Cohere, GitHub
- 700+ test cases covering new functionality

✅ Backward compatibility maintained with gradual migration path

* fix(deps): convert SSH git URLs to HTTPS for GitHub runner compatibility

- Changed git+ssh://[email protected] URLs to git+https://github.com URLs
- Fixes git clone failures in CI/CD environments that lack SSH key access
- Updated both main dependencies and hatch-static-analysis dependencies

* feat: restore deprecated tools for backward compatibility and update deps

- Add use_llm and agent_graph tools back with deprecation warnings
- These tools will be removed in next major release
- Move Stability AI documentation to docs/stability_ai_tool.md
- Update pyproject.toml dependencies to use proper version ranges
- Add comprehensive test suites for both deprecated tools
- Maintain backward compatibility while guiding users to new APIs

* build: replace git dependency with version constraint for strands-agents

* refactor(models): move models to utils/models directory

- Move all model files from strands_tools/models/ to strands_tools/utils/models/
- Update import statements in graph.py, think.py, use_agent.py, and workflow.py
- Reorganize codebase structure for better organization

* fix(deps): remove duplicate strands-agents dependency

- Removed duplicate strands-agents[a2a] dependency from pyproject.toml
- Keeps only the base strands-agents dependency

---------

Co-authored-by: Arron <[email protected]>

Author: cagataycali

.gitignore

@@ -13,3 +13,4 @@ errors/
 repl_state/
 venv/
 *.egg-info
+.DS_Store

src/strands_tools/stability_ai_tool.md renamed to docs/stability_ai_tool.md

@@ -142,4 +142,4 @@ The available parameters that can be passed to the tool are:
 ## References
 
 - [Strands Agents Tools](https://strandsagents.com/latest/user-guide/concepts/tools/tools_overview/)
-- [Stability AI Stable Image Generation](https://platform.stability.ai/docs/api-reference#tag/Generate)
+- [Stability AI Stable Image Generation](https://platform.stability.ai/docs/api-reference#tag/Generate)

src/strands_tools/agent_graph.py

@@ -514,6 +514,11 @@ def agent_graph(tool: ToolUse, **kwargs: Any) -> ToolResult:
     messages = kwargs.get("messages")
     tool_config = kwargs.get("tool_config")
 
+    logger.warning(
+        "DEPRECATION WARNING: agent_graph will be removed in the next major release. "
+        "Migration path: replace agent_graph calls with graph for equivalent functionality."
+    )
+
     try:
         # Create tool context
         tool_context = {