fix: improve MiniMax adaptor from PR #318 review (#319)

* feat: add MiniMax AI as LLM platform adaptor

Original implementation by octo-patch in PR #318.
This commit includes comprehensive improvements and documentation.

Code Improvements:
- Fix API key validation to properly check JWT format (eyJ prefix)
- Add specific exception handling for timeout and connection errors
- Remove unused variable in upload method

Dependencies:
- Add MiniMax to [all-llms] extra group in pyproject.toml

Tests:
- Remove duplicate setUp method in integration test class
- Add 4 new test methods:
  * test_package_excludes_backup_files
  * test_upload_success_mocked (with OpenAI mocking)
  * test_upload_network_error
  * test_upload_connection_error
  * test_validate_api_key_jwt_format
- Update test_validate_api_key_valid to use JWT format keys
- Fix test assertions for error message matching

Documentation:
- Create comprehensive MINIMAX_INTEGRATION.md guide (380+ lines)
- Update MULTI_LLM_SUPPORT.md with MiniMax platform entry
- Update 01-installation.md extras table
- Update INTEGRATIONS.md AI platforms table
- Update AGENTS.md adaptor import pattern example
- Fix README.md platform count from 4 to 5

All tests pass (33 passed, 3 skipped)
Lint checks pass

Co-authored-by: octo-patch <octo-patch@users.noreply.github.com>

* fix: improve MiniMax adaptor — typed exceptions, key validation, tests, docs

- Remove invalid "minimax" self-reference from all-llms dependency group
- Use typed OpenAI exceptions (APITimeoutError, APIConnectionError)
  instead of string-matching on generic Exception
- Replace incorrect JWT assumption in validate_api_key with length check
- Use DEFAULT_API_ENDPOINT constant instead of hardcoded URLs (3 sites)
- Add Path() cast for output_path before .is_dir() call
- Add sys.modules mock to test_enhance_missing_library
- Add mocked test_enhance_success with backup/content verification
- Update test assertions for new exception types and key validation
- Add MiniMax to __init__.py docstrings (module, get_adaptor, list_platforms)
- Add MiniMax sections to MULTI_LLM_SUPPORT.md (install, format, API key,
  workflow example, export-to-all)

Follows up on PR #318 by @octo-patch (feat: add MiniMax AI as LLM platform adaptor).

Co-Authored-By: Octopus <octo-patch@users.noreply.github.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: octo-patch <octo-patch@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

README.md

@@ -248,7 +248,7 @@ Instead of spending days on manual preprocessing, Skill Seekers:
 - ✅ **Backward Compatible** - Legacy single-source configs still work
 
 ### 🤖 Multi-LLM Platform Support
-- ✅ **4 LLM Platforms** - Claude AI, Google Gemini, OpenAI ChatGPT, Generic Markdown
+- ✅ **5 LLM Platforms** - Claude AI, Google Gemini, OpenAI ChatGPT, MiniMax AI, Generic Markdown
 - ✅ **Universal Scraping** - Same documentation works for all platforms
 - ✅ **Platform-Specific Packaging** - Optimized formats for each LLM
 - ✅ **One-Command Export** - `--target` flag selects platform
@@ -260,6 +260,7 @@ Instead of spending days on manual preprocessing, Skill Seekers:
 | **Claude AI** | ZIP + YAML | ✅ Auto | ✅ Yes | ANTHROPIC_API_KEY | ANTHROPIC_BASE_URL |
 | **Google Gemini** | tar.gz | ✅ Auto | ✅ Yes | GOOGLE_API_KEY | - |
 | **OpenAI ChatGPT** | ZIP + Vector Store | ✅ Auto | ✅ Yes | OPENAI_API_KEY | - |
+| **MiniMax AI** | ZIP + Knowledge Files | ✅ Auto | ✅ Yes | MINIMAX_API_KEY | - |
 | **Generic Markdown** | ZIP | ❌ Manual | ❌ No | - | - |
 
 ```bash
@@ -277,6 +278,11 @@ pip install skill-seekers[openai]
 skill-seekers package output/react/ --target openai
 skill-seekers upload react-openai.zip --target openai
 
+# MiniMax AI
+pip install skill-seekers[minimax]
+skill-seekers package output/react/ --target minimax
+skill-seekers upload react-minimax.zip --target minimax
+
 # Generic Markdown (universal export)
 skill-seekers package output/react/ --target markdown
 # Use the markdown files directly in any LLM
@@ -312,6 +318,9 @@ pip install skill-seekers[gemini]
 # Install with OpenAI support
 pip install skill-seekers[openai]
 
+# Install with MiniMax support
+pip install skill-seekers[minimax]
+
 # Install with all LLM platforms
 pip install skill-seekers[all-llms]
 ```
@@ -698,21 +707,21 @@ skill-seekers install --config react --dry-run
 
 ## 📊 Feature Matrix
 
-Skill Seekers supports **4 LLM platforms**, **17 source types**, and full feature parity across all targets.
+Skill Seekers supports **5 LLM platforms**, **17 source types**, and full feature parity across all targets.
 
-**Platforms:** Claude AI, Google Gemini, OpenAI ChatGPT, Generic Markdown
+**Platforms:** Claude AI, Google Gemini, OpenAI ChatGPT, MiniMax AI, Generic Markdown
 **Source Types:** Documentation websites, GitHub repos, PDFs, Word (.docx), EPUB, Video, Local codebases, Jupyter Notebooks, Local HTML, OpenAPI/Swagger, AsciiDoc, PowerPoint (.pptx), RSS/Atom feeds, Man pages, Confluence wikis, Notion pages, Slack/Discord chat exports
 
 See [Complete Feature Matrix](docs/FEATURE_MATRIX.md) for detailed platform and feature support.
 
 ### Quick Platform Comparison
 
-| Feature | Claude | Gemini | OpenAI | Markdown |
-|---------|--------|--------|--------|----------|
-| Format | ZIP + YAML | tar.gz | ZIP + Vector | ZIP |
-| Upload | ✅ API | ✅ API | ✅ API | ❌ Manual |
-| Enhancement | ✅ Sonnet 4 | ✅ 2.0 Flash | ✅ GPT-4o | ❌ None |
-| All Skill Modes | ✅ | ✅ | ✅ | ✅ |
+| Feature | Claude | Gemini | OpenAI | MiniMax | Markdown |
+|---------|--------|--------|--------|--------|----------|
+| Format | ZIP + YAML | tar.gz | ZIP + Vector | ZIP + Knowledge | ZIP |
+| Upload | ✅ API | ✅ API | ✅ API | ✅ API | ❌ Manual |
+| Enhancement | ✅ Sonnet 4 | ✅ 2.0 Flash | ✅ GPT-4o | ✅ M2.7 | ❌ None |
+| All Skill Modes | ✅ | ✅ | ✅ | ✅ | ✅ |
 
 ---