fix: keep Linux helper reexec stable after binary replacement

[Chillizu]

Summary

• prefer /proc/self/exe when spawning the Linux Landlock helper
• fall back to current_exe() when procfs is unavailable
• add coverage for the helper executable selection

Why

If the CatDesk binary is replaced while the process is still running, current_exe() can resolve to the old deleted pathname. The next run_command / background command then fails to spawn the Landlock helper with ENOENT. /proc/self/exe continues to reference the live executable inode, so self-reexec remains available across an atomic binary replacement.

Verification

• cargo test --release: 219 passed, 0 failed
• changed Rust file formatted with rustfmt
• git diff --check: clean

Note: repository-wide cargo fmt --check currently reports an unrelated pre-existing formatting diff in src/browser.rs on main.

Summary by CodeRabbit

• Bug Fixes
  • Improved reliability when launching the CatDesk helper command in Linux sandboxed environments.
  • The application now more consistently identifies its executable, with a fallback for systems where the preferred path is unavailable.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Team

Run ID: c8433f56-20aa-4e86-b38c-853b650bb6e5

📥 Commits

Reviewing files that changed from the base of the PR and between bfac47b and ad77f2e.

📒 Files selected for processing (1)

• src/linux_sandbox.rs

Included review availability: Your plan provides up to 2 included reviews per hour; 1 remains after this review.

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📝 Walkthrough

Walkthrough

The sandbox helper command now resolves its executable from /proc/self/exe when available and falls back to current_exe(). A test verifies the preferred path. Landlock imports are reformatted.

Changes

Helper executable resolution

Layer / File(s)	Summary
Executable lookup and validation src/linux_sandbox.rs	The new helper_executable helper prefers /proc/self/exe and falls back to std::env::current_exe(). helper_command uses the helper, and a test verifies the preferred path. Landlock imports are reordered.

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

Merge Risk: ⚪ Minimal · up to ad77f

Sandbox helper reexecution now uses the live executable through /proc/self/exe when available, preserving operation after atomic binary replacement while retaining the existing fallback. The change is ready to merge.

Suggested reviewers: xeift

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 6 functions across 1 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: keeping Linux helper re-execution stable after binary replacement.
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.

• Fix all pre-merge checks with AI

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[Xeift]

@Chillizu Yo, sorry for the late response. I've been busy and recently moved back home, so I haven't been able to review PRs in time.

Since we switched from Landlock to Bubblewrap in #14, this fix is no longer needed on main, so I've decided to close this PR. Truly appreciate the contribution!