fix(for): correct semantics for "for" without "in"

[reubeno]

When in is not specified with a for clause, we need to enumerate positional arguments instead (i.e., $@).

This scenario was getting parsed correctly, but not correctly interpreted.

Resolves #342. Thanks to @ko1nksm for identifying the problem and filing a bug report on it!

[Copilot]

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

[Copilot]

The trace message for the case without 'in' is unclear. It should indicate that positional parameters are being used. Suggestion: shell.trace_command(std::format!("for {} (using positional parameters)", self.variable_name))?;

Suggested change

	shell.trace_command(std::format!("for {}", self.variable_name,))?;
	shell.trace_command(std::format!("for {} (using positional parameters)", self.variable_name))?;

[github-actions]

Test Results

    3 files     14 suites   6m 6s ⏱️
  614 tests   614 ✅ 0 💤 0 ❌
1 828 runs  1 828 ✅ 0 💤 0 ❌

Results for commit f08c055.

[github-actions]

Performance Benchmark Report

Benchmark name	Baseline (μs)	Test/PR (μs)	Delta (μs)	Delta %
clone_shell_object	16.50 μs	16.33 μs	-0.18 μs	⚪ Unchanged
eval_arithmetic	0.18 μs	0.18 μs	0.00 μs	⚪ Unchanged
expand_one_string	1.58 μs	1.61 μs	0.03 μs	⚪ Unchanged
for_loop	32.57 μs	32.98 μs	0.41 μs	⚪ Unchanged
function_call	3.33 μs	3.34 μs	0.01 μs	⚪ Unchanged
instantiate_shell	48.62 μs	49.03 μs	0.40 μs	⚪ Unchanged
instantiate_shell_with_init_scripts	22252.98 μs	22072.52 μs	-180.46 μs	⚪ Unchanged
parse_bash_completion	1665.44 μs	1667.31 μs	1.87 μs	⚪ Unchanged
parse_sample_script	1.78 μs	1.77 μs	-0.01 μs	⚪ Unchanged
run_echo_builtin_command	16.08 μs	15.86 μs	-0.22 μs	⚪ Unchanged
run_one_external_command	2394.58 μs	2443.91 μs	49.33 μs	🟠 +2.06%
tokenize_sample_script	2.83 μs	2.94 μs	0.11 μs	🟠 +3.96%

Code Coverage Report: Only Changed Files listed

Package	Base Coverage	New Coverage	Difference
brush-core/src/builtins/set.rs	🟠 60.8%	🟠 61.93%	🟢 1.13%
brush-core/src/commands.rs	🟢 86.83%	🟢 86.9%	🟢 0.07%
brush-core/src/interp.rs	🟢 91.07%	🟢 91.18%	🟢 0.11%
brush-core/src/jobs.rs	🔴 43.1%	🔴 37.07%	🔴 -6.03%
brush-parser/src/parser.rs	🟢 99.05%	🟢 99.16%	🟢 0.11%
Overall Coverage	🟢 74.73%	🟢 74.68%	🔴 -0.05%

Minimum allowed coverage is 70%, this run produced 74.68%