🔒 Fix arbitrary file write / path traversal via session_id

[google-labs-jules]

🎯 What: Fixed an arbitrary file write / path traversal vulnerability where the session_id parameter (derived from unvalidated JSON tool inputs) was unsafely interpolated into the ~/.claude/.seal_guard_state_{session_id}.json file path.

⚠️ Risk: An attacker-controlled session_id like ../../../etc/passwd or similar path traversal sequences could write state files across the filesystem, potentially overwriting user files or causing unexpected application behavior if sensitive files were corrupted or overwritten.

🛡️ Solution: Used re.sub(r"[^a-zA-Z0-9_-]", "_", str(session_id)) to sanitize any hazardous characters from the string before using it to build the file path. Appended a new test_security_guard.py suite demonstrating that it handles normal session ids and properly mitigates path traversal attacks.

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PR created automatically by Jules for task 7162296469594203018 started by @zknpr

[google-labs-jules]

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[zknpr]

Closing in favor of #17, which consolidates all 16 open hook PRs into one coherent change (they overlapped and conflicted with each other, so they could not be merged independently). Superseded by #17. This fixed only security_guard and left secret_scanner vulnerable; #17 fixes both in the shared util. Your .gitignore and the path-traversal regression test idea were kept.

[google-labs-jules]

Closing in favor of #17, which consolidates all 16 open hook PRs into one coherent change (they overlapped and conflicted with each other, so they could not be merged independently). Superseded by #17. This fixed only security_guard and left secret_scanner vulnerable; #17 fixes both in the shared util. Your .gitignore and the path-traversal regression test idea were kept.

Understood. Acknowledging that this PR is superseded by #17 and stopping work on this task.