fix(core): canonicalize macos session paths

[AidenGeunGeun]

Issue for this PR

Closes #44014

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

Resolves existing macOS paths to their on-disk component casing, then uses that path for session creation, directory filters, and moves. Other platforms and missing paths keep their current behavior.

How did you verify your code works?

• bun test test/session-create.test.ts in packages/core (35 pass)
• bun typecheck in packages/core and packages/util
• repository pre-commit typecheck (33 tasks)

Screenshots / recordings

N/A

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

[github-actions]

Thanks for your contribution!

This PR doesn't have a linked issue. All PRs must reference an existing issue.

Please:

1. Open an issue describing the bug/feature (if one doesn't exist)
2. Add Fixes #<number> or Closes #<number> to this PR description

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