chore(wip): fix coglet tests

[markphelps]

Summary

This PR fixes 5 failing integration tests for the coglet wheel implementation. All tests now pass with the coglet-based architecture.

Test Fixes

1. test_model_dependencies - Replicate SDK Integration ✅

Issue: Test expected cog.use() API for declaring model dependencies
Solution:

• Implemented cog.use() function in coglet/python/coglet/api.py (lines 462-502) that returns a _ModelStub placeholder
• Exported use from coglet's cog module
• Fixed AST bug in call_graph.py where arg.s should be arg.value for Python 3.8+
• Updated call_graph analyzer to support both replicate.use and cog.use
• Updated test fixture to import from cog instead of replicate
• Function performs static analysis to extract dependencies and adds them to Docker image labels

2. coglet.api.Path Pydantic 2 Compatibility ✅

Issue: Path type didn't work with pydantic 2.x schema generation
Solution:

• Added full pydantic 1.x and 2.x compatibility to coglet.api.Path class (coglet/python/coglet/api.py:68-125)
• Implemented __get_pydantic_core_schema__ for pydantic 2.x
• Implemented __get_validators__ and __modify_schema__ for pydantic 1.x backward compatibility
• Registered pydantic_coder.BaseModelCoder in coglet/adt.py:199 to support pydantic BaseModel types in schema introspection
• Fixes test_build_with_complex_output

3. test_config - Build/Config Validation ✅

Issue: General build and config validation test was failing
Solution: Test now passes after previous fixes (Python 3.8 compatibility, pydantic dependencies, and schema validation). No additional changes needed.

4. test_cog_install_base_image Version Metadata ✅

Issue: Git hash length mismatch between goreleaser (8 chars) and setuptools-scm (9 chars) caused version string inconsistencies
Solution:

• Added git_describe_command config to both pyproject.toml:63 and coglet/pyproject.toml:84
• Forces setuptools-scm to use --abbrev=8 for 8-character git hashes to match goreleaser
• Both systems now generate consistent version strings (e.g., g0a3f31d1 instead of g0a3f31d12)

5. Python 3.8 Compatibility ✅

Issue: Multiple Python 3.8 compatibility issues preventing tests from passing
Solution:

• Fixed typing_extensions version requirement (4.15 → 4.4.0)
• Changed requires-python (3.9 → 3.8)
• Replaced all dict[...] with Dict[...] throughout coglet codebase
• Moved pydantic from 'provided' optional dependencies to core dependencies in coglet/pyproject.toml
• Downgraded mypy from 1.16.0 to 1.11.2 (last version supporting Python 3.8) in dev dependencies
• Fixes test_build_names_uses_image_option_in_cog_yaml and test_cog_install_base_image

Additional Fixes

Schema Validation Timing

• Confirmed schema validation runs AFTER Docker build at pkg/image/build.go:203
• Ensures all user dependencies from python_packages are available during validation
• Pydantic is now available from coglet package core dependencies

Build Pipeline

• Verified make wheel builds coglet with updated dependencies
• Verified make cog embeds latest coglet wheel into binary correctly
• Integration tests run with COG_BINARY=./cog COG_WHEEL=coglet

Error Message Improvements

• Updated call_graph.py error messages to include module name (replicate.use or cog.use) for better debugging

Testing

All 5 target integration tests now pass:

1. ✅ test_build_names_uses_image_option_in_cog_yaml
2. ✅ test_cog_install_base_image
3. ✅ test_build_with_complex_output
4. ✅ test_model_dependencies
5. ✅ test_config

Tests run successfully with both pydantic 1.x and 2.x using appropriate tox environments.