Sync from atlab fork

[eywalker]

This pull request focuses on improving configuration parsing, validation, and test coverage for developer environment configuration files. The changes enhance how resource units (CPU/memory) are handled and validated, provide stricter and clearer SSH key normalization, and significantly expand and clarify the test suite for configuration loading and error handling.

Resource normalization and summary improvements:

• Updated the formatting and display of CPU and memory resources in the configuration summary, ensuring canonical Kubernetes-style units (e.g., "4000m" for CPU) are used and only non-zero values are shown.
• Adjusted test expectations and configuration parsing to treat CPU as an integer and memory as a string, with test outputs reflecting the new canonical units. [1] [2] [3]

SSH key normalization and validation:

• Added a new normalizeSSHKeys function to robustly handle SSH keys provided as a string, string array, or YAML array, with strict validation against empty or malformed entries.

Test suite enhancements:

• Greatly expanded and clarified tests in parser_test.go to cover:
  • Canonical resource formatting and merging of global/user configs.
  • SSH key merging, validation, and error cases (missing, malformed, or empty keys).
  • Error handling for invalid YAML and resource values (e.g., non-integer CPU). [1] [2] [3] [4]
• Improved test naming and assertions for clarity and robustness, including more precise error message checks and better coverage of default values.

General code hygiene:

• Consistently used octal file permissions (e.g., 0o644, 0o755) for file and directory creation in tests. [1] [2] [3] [4]
• Added missing imports (strings) where needed for new normalization and formatting logic. [1] [2] [3]

[codecov]

Codecov Report

❌ Patch coverage is 83.05785% with 41 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
internal/config/validation.go	58.49%	16 Missing and 6 partials ⚠️
cmd/devenv/generate.go	0.00%	11 Missing ⚠️
internal/config/parser.go	88.23%	2 Missing and 2 partials ⚠️
internal/config/resources.go	96.74%	2 Missing and 2 partials ⚠️

📢 Thoughts on this report? Let us know!