feat(options): implement noclobber option (a.k.a. -C)

[reubeno]

• Adds support for -C on command line, via set, etc.
• Adds basic compat tests to check.

Copilot reviewed 5 out of 6 changed files in this pull request and generated no comments.

Files not reviewed (1)

• brush-core/src/interp.rs: Evaluated as low risk

Comments suppressed due to low confidence (2)

brush-shell/src/args.rs:48

• The comment correctly describes the option. No spelling or grammar mistakes found.

/// Enable noclobber shell option.

brush-core/src/shell.rs:127

• [nitpick] The variable name disallow_overwriting_regular_files_via_output_redirection is too lengthy. Consider renaming it to noclobber for better readability.

pub disallow_overwriting_regular_files_via_output_redirection: bool,

[github-actions]

Test Results

    2 files      9 suites   1m 24s ⏱️
  556 tests   556 ✅ 0 💤 0 ❌
1 098 runs  1 098 ✅ 0 💤 0 ❌

Results for commit 591d200.

[github-actions]

Performance Benchmark Report

Benchmark name	Baseline (μs)	Test/PR (μs)	Delta (μs)	Delta %
expand_one_string	3.32 μs	3.48 μs	0.16 μs	🟠 +4.66%
instantiate_shell	59.40 μs	58.69 μs	-0.71 μs	⚪ Unchanged
instantiate_shell_with_init_scripts	29140.74 μs	29478.29 μs	337.55 μs	⚪ Unchanged
parse_bash_completion	2700.18 μs	2676.96 μs	-23.22 μs	⚪ Unchanged
parse_sample_script	4.14 μs	4.09 μs	-0.05 μs	⚪ Unchanged
run_echo_builtin_command	89.34 μs	89.28 μs	-0.05 μs	⚪ Unchanged
run_one_builtin_command	105.38 μs	106.69 μs	1.32 μs	⚪ Unchanged
run_one_external_command	1886.92 μs	1867.32 μs	-19.60 μs	⚪ Unchanged
run_one_external_command_directly	960.30 μs	971.88 μs	11.57 μs	⚪ Unchanged

Code Coverage Report: Only Changed Files listed

Package	Base Coverage	New Coverage	Difference
brush-core/src/builtins/set.rs	🟠 57.23%	🟠 60.69%	🟢 3.46%
brush-core/src/interp.rs	🟢 91.27%	🟢 92.35%	🟢 1.08%
brush-core/src/jobs.rs	🔴 37.23%	🔴 42.42%	🟢 5.19%
brush-core/src/options.rs	🟢 89.8%	🟢 90.2%	🟢 0.4%
brush-core/src/shell.rs	🟢 82.29%	🟢 82.42%	🟢 0.13%
brush-shell/src/args.rs	🟠 62.22%	🟠 60.87%	🔴 -1.35%
brush-shell/src/main.rs	🟢 90.38%	🟢 90.51%	🟢 0.13%
Overall Coverage	🟢 76.95%	🟢 77.16%	🟢 0.21%

Minimum allowed coverage is 70%, this run produced 77.16%