fix: bash tool memory leak

[Jiwenshang]

Issue for this PR

Closes #21319

Type of change

• Bug fix

What does this PR do?

fix bash tool memory leak

How did you verify your code works?

UT & test manually

Screenshots / recordings

If this is a UI change, please include a screenshot or recording.

Checklist

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

If you do not follow this template your PR will be automatically rejected.

[github-actions]

Hey! Your PR title fix bash memory leak doesn't follow conventional commit format.

Please update it to start with one of:

• feat: or feat(scope): new feature
• fix: or fix(scope): bug fix
• docs: or docs(scope): documentation changes
• chore: or chore(scope): maintenance tasks
• refactor: or refactor(scope): code refactoring
• test: or test(scope): adding or updating tests

Where scope is the package name (e.g., app, desktop, opencode).

See CONTRIBUTING.md for details.

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

Based on my search, here are the potentially related PRs:

Most Relevant:

• feat(bash): stream large output to tmpfile with filtering and GC #8953 - feat(bash): stream large output to tmpfile with filtering and GC - Previous bash memory leak fix with similar scope
• fix: resolve memory leak issues across multiple subsystems #14650 - fix: resolve memory leak issues across multiple subsystems - General memory leak fixes
• fix: consolidate memory leak fixes from #14650 and #8953 #15435 - fix: consolidate memory leak fixes from fix: resolve memory leak issues across multiple subsystems #14650 and feat(bash): stream large output to tmpfile with filtering and GC #8953 - Consolidates prior bash memory fixes

Other related memory leak fixes:

• fix: clear tool output and attachments when pruning to prevent memory leak #7049 - clear tool output and attachments when pruning to prevent memory leak
• fix(opencode): memory leaks in session handling #10392 - memory leaks in session handling
• fix: address 6 memory leaks for long-running sessions #13594 - address 6 memory leaks for long-running sessions
• fix(opencode): robust process exit detection for child processes #15757 - robust process exit detection for child processes
• fix: resolve multiple memory leaks causing unbounded growth #16695 - resolve multiple memory leaks causing unbounded growth
• fix(opencode): reduce memory usage and database bloat in long-running instances #16730 - reduce memory usage and database bloat in long-running instances

Note: PR #21192 (mentioned in "Closes #21192") appears to be a TUI fix unrelated to bash memory leaks.

[github-actions]

Thanks for updating your PR! It now meets our contributing guidelines. 👍

[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

See CONTRIBUTING.md for details.