feat: implement Aider AI pair programming support (#17)

* feat: implement Aider AI pair programming support

  - Add comprehensive Aider Docker image with Python 3.12 and system pip installation
  - Implement aider_plugin.py for secure API key management and environment configuration
  - Support multiple LLM providers: OpenAI, Anthropic, DeepSeek, Gemini, OpenRouter
  - Add persistent configuration for ~/.aider/ and ~/.cache/aider/ directories
  - Create comprehensive documentation with usage examples and troubleshooting
  - Include automated test suite with 6 test categories covering all functionality
  - Update container.py to support DEEPSEEK_API_KEY and GEMINI_API_KEY
  - Integrate with Cubbi CLI for seamless session management

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

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

* Fix pytest for aider

* Fix pre-commit

---------

Co-authored-by: Your Name <you@example.com>

.github/workflows/pytests.yml

@@ -30,10 +30,11 @@ jobs:
       - name: Install all dependencies
         run: uv sync --frozen --all-extras --all-groups
 
-      - name: Build goose image
+      - name: Build required images
         run: |
           uv tool install --with-editable . .
           cubbi image build goose
+          cubbi image build aider
 
       - name: Tests
         run: |