fix(ccusage): harden PATH enrichment and add regression tests

[robinebers]

Description

• Rework ccusage PATH enrichment to use OS-safe path handling via split_paths + join_paths.
• Unify runner probe/execution command setup so both use the same PATH override contract.
• Add regression tests for PATH ordering, deduplication, split/join round-trip behavior, and command PATH wiring.

Related Issue

• N/A

Type of Change

• Bug fix
• New feature
• New provider plugin
• Documentation
• Performance improvement
• Other (describe below)

Testing

• I ran bun run build and it succeeded
• I ran bun run test and all tests pass
• I tested the change locally with bun tauri dev
• I ran cargo test in src-tauri (45 passing)
• I ran cargo test ccusage --lib in src-tauri (16 passing)
• I ran bun run test:coverage (tests passed; command failed on existing unrelated coverage thresholds in app hooks/components)

Screenshots

• Not applicable (no UI changes)

Checklist

• I read CONTRIBUTING.md
• My PR targets the main branch
• I did not introduce new dependencies without justification

Made with Cursor

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Note

^{Cursor Bugbot is generating a summary for commit 914ae10. Configure here.}

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Summary by cubic

Hardened ccusage PATH handling with OS-safe split/join and a shared command configuration so runner detection and execution behave consistently across environments. Adds focused regression tests to lock in ordering, deduplication, and PATH wiring.

• Bug Fixes

  • Build PATH using split_paths/join_paths; preserve order and dedupe entries.
  • Prepend home bin dirs (~/.bun/bin, ~/.nvm/current/bin, ~/.local/bin) and defaults (/opt/homebrew/bin, /usr/local/bin).
  • Use one configure_ccusage_command and enriched PATH for both runner probing and execution.

• Tests

  • Validate PATH ordering, deduplication, and split/join round-trip.
  • Verify PATH is correctly set for commands when provided, and skipped when absent.

^{Written for commit 914ae10. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 1 file

[davidarny]

LGTM!