Android and Termux permission boundaries

1. Install applications from trustworthy repositories and review individual permission prompts.

2. File access granted to Termux is not permission to inspect another person's files.

3. When permission denied appears, check file ownership and path before changing access.

4. Avoid broad permission changes when a narrower project-specific fix is sufficient.

5. Exercise: document a permission error and the smallest reversible change that solves it.

Scope: Education and testing on owned or explicitly authorized systems only.