fix: CLI-only skills remain discoverable when project path casing differs

[hatayama]

Summary

• CLI-only skills remain discoverable when the current project path uses different letter casing on Windows or macOS.
• Linux keeps case-sensitive path identity.

User Impact

• Previously, the CLI-only source gate compared normalized project paths with an ordinal string comparison. Equivalent project paths with different casing could therefore be rejected on the default case-insensitive Windows and macOS filesystems.
• Discovery now follows the editor platform's path identity policy: case-insensitive on Windows/macOS and ordinal on Linux.

Changes

• Extracted both CLI-only path comparisons into one helper that receives the runtime platform explicitly.
• Kept the extraction behavior-preserving in its own commit, then applied the platform policy in a second commit.
• Added a deterministic Windows/macOS/Linux contract test.
• Normalize optional trailing directory separators while preserving filesystem roots.
• Kept Go unchanged because its CLI-only source path has no current-project identity gate.
• Avoided per-volume filesystem probing because it would add I/O and complexity to a narrow source-discovery gate.

Test Scope Note

• A final skill-set integration test cannot observe this gate failure in the repository checkout: when the dedicated CLI-only root is rejected, Packages/src is still enumerated later as a direct package root and rediscovers the same Editor/CliOnlyTools~ files. The attempted integration test passed before the fix and was removed because it did not constrain the faulty comparison.
• The contract test targets the actual path identity seam used by both GetCliOnlySkillSourceRoot and IsCliOnlySkillSourceRoot.

Verification

• TDD Red: with the extracted ordinal-only helper, the Windows and macOS cases failed while Linux passed (2 failed, 1 passed).
• TDD Green: all three platform cases passed after applying the policy.
• Review TDD Red/Green: trailing-separator equivalence failed on all three platform cases before normalization and passed afterward.
• Repo-local Unity compile: 0 errors, 0 warnings.
• SkillInstallLayoutTests: 19 passed.
• ToolSkillSynchronizerTests: 52 passed.
• git diff --check.

Review Response

• Accepted cubic's trailing-separator finding after confirming in the active Unity runtime that Path.GetFullPath preserves the separator. The fix uses root-safe normalization rather than a plain TrimEnd that could collapse / or a drive root.

Compatibility

• Source discovery ordering and wire formats are unchanged, so no protocol version bump is required.

[coderabbitai]

📝 Walkthrough

Walkthrough

SkillSourceRootEnumerator's path comparison logic is refactored to use a new platform-aware HaveSamePathIdentityAtPlatform helper, applying case-insensitive comparison on Windows/macOS editors and case-sensitive comparison elsewhere. A new parameterized test validates this behavior across platforms.

Changes

Platform-aware path identity

Layer / File(s)	Summary
Path identity helper and call sites Packages/src/Editor/Infrastructure/SkillSetup/SkillSourceRootEnumerator.cs	Adds internal HaveSamePathIdentityAtPlatform method that compares full paths using OrdinalIgnoreCase for WindowsEditor/OSXEditor and Ordinal otherwise; GetCliOnlySkillSourceRoot and IsCliOnlySkillSourceRoot now use this helper instead of a fixed ordinal comparison.
Cross-platform casing test Assets/Tests/Editor/SkillInstallLayoutTests.cs	Adds a parameterized NUnit test verifying that casing-differing paths are treated as identical on WindowsEditor/OSXEditor but distinct on LinuxEditor.

Estimated code review effort: 2 (Simple) | ~10 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly summarizes the main fix: preserving CLI-only skill discovery when project path casing differs.
Description check	✅ Passed	The description is detailed and directly related to the path-casing discovery fix and its tests.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/hatayama/normalize-cli-only-root-casing

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[cubic-dev-ai]

All reported issues were addressed across 2 files

<sub>Reply with feedback, questions, or to request a fix.

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