Set up tools structures

[ohdearquant]

PR Description: Set Up Tools Structures & Minor Error Handling in iModel

This PR refactors and expands LionAGI to include initial placeholders for various tools (e.g. browser, code, file) under a consistent directory structure. It also includes a minor enhancement for handling missing api_key in iModel when requires_api_key=True, raising a clear ValueError if none is found.

Key Changes

1. Tools Directory Structure

   • New lionagi/tools folder containing subfolders like browser, code, file, and their respective providers.
   • Each subfolder now has an __init__.py and placeholder modules (e.g. aider_.py, docling_.py) as initial scaffolding.
   • A base.py in tools that sets up a minimal foundation for tool classes.

2. Minor iModel Error Handling

   • In iModel.__init__(), if api_key is not provided (and requires_api_key=True), the code now raises ValueError("API key must be provided").
   • This ensures the usage pattern is clearer for providers requiring an explicit API key.

3. Version Bump

   • Bumps version from 0.9.2 to 0.9.3 in lionagi/version.py and pyproject.toml.

4. Housekeeping

   • Adds file headers with SPDX license notes in newly introduced files.
   • Minor additions in utils or placeholder references for upcoming expansions (e.g., docling support in reader.py).

Rationale

• Tools are part of the LionAGI architecture to handle specialized actions (e.g. browsing, coding, file I/O). This PR lays the initial foundation.
• Improving iModel error messages around API keys prevents hidden misconfigurations and aligns with “fail fast” best practices.

Next Steps

• Flesh out each provider inside tools/browser/providers and tools/code/providers, finalizing method-level logic.
• Confirm synergy with the Action system for consistent function-calling from LLM prompts.
• Test newly introduced scaffolding in real usage scenarios.

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