fix: prevent false positives in recursive delete detection

[cutepawss]

Problem

The regex pattern for detecting recursive delete commands in tools/approval.py produces false positives for any rm command where the filename starts with the letter r.

Root cause: The pattern \brm\s+(-[^\s]*)?r makes the dash-flag group (-[^\s]*)? optional. When the filename doesn't start with -, the group matches nothing, and the trailing r matches the first character of the filename instead of a flag.

Examples of false positives:

Command	Expected	Actual
rm readme.txt	✅ Safe	❌ Flagged as 'recursive delete'
rm requirements.txt	✅ Safe	❌ Flagged
rm report.csv	✅ Safe	❌ Flagged
rm README.md	✅ Safe	❌ Flagged
rm results.json	✅ Safe	❌ Flagged
rm robots.txt	✅ Safe	❌ Flagged

This causes unnecessary approval prompts for the user when the agent tries to delete files whose names start with 'r'.

Fix

Make the dash mandatory so only actual flags are matched:

- (r'\brm\s+(-[^\s]*)?r', "recursive delete"),
+ (r'\brm\s+-[^\s]*r', "recursive delete"),

The change from (-[^\s]*)? (optional group) to -[^\s]* (required dash) ensures the r is always part of a CLI flag like -r, -rf, -rfv, or -fr — never part of a filename.

Tests Added

Added 15 new tests in tests/tools/test_approval.py across two classes:

TestRmFalsePositiveFix (8 regression tests):

• Verifies that rm readme.txt, rm requirements.txt, rm report.csv, rm results.json, rm robots.txt, rm run.sh, rm -f readme.txt, rm -v readme.txt are all correctly identified as safe

TestRmRecursiveFlagVariants (7 tests):

• Verifies that rm -r, rm -rf, rm -rfv, rm -fr, rm -irf, rm --recursive, sudo rm -rf are all still correctly caught as dangerous

29 passed in 0.53s (14 existing + 15 new, 0 failures)

Scope

• tools/approval.py: 1-line regex fix (line 25)
• tests/tools/test_approval.py: 15 new regression tests
• No behavior change for actual recursive delete commands