fix: sanitize subprocess call in gmtplot.py

[orbisai0security]

Summary

Fix high severity security issue in docs/source/_extensions/gmtplot.py.

Vulnerability

Field	Value
ID	V-001
Severity	HIGH
Scanner	multi_agent_ai
Rule	V-001
File	docs/source/_extensions/gmtplot.py:173

Description: The gmtplot.py Sphinx extension invokes subprocess.run() with shell=True at lines 173, 174, and 197, incorporating ps_images[0] — a file path derived from processed documentation source files — directly into the shell command string. When shell=True is used, the entire command string is passed to the OS shell interpreter (/bin/sh), which means any shell metacharacters present in ps_images[0] (such as semicolons, backticks, pipes, or dollar signs) will be interpreted as shell syntax rather than literal path characters. An attacker who can contribute RST documentation files to the repository can craft a filename or path that injects additional shell commands.

Changes

• docs/source/_extensions/gmtplot.py

Verification

• Build passes
• Scanner re-scan confirms fix
• LLM code review passed

---

Automated security fix by OrbisAI Security

[Dengda98]

Thanks!