Improve password generator randomness

[rautava]

Overview

This PR enhances the password generation logic to produce stronger, more unpredictable results while modernizing the development workflow. It introduces automated testing, updates scripts, and improves documentation for maintainability.

Changes

Password Generator

• Improved randomness in generated passwords.
• Ensures consistent distribution across character classes.
• Reset content script settings to defaults for stability.

Testing & CI

• Added Deno test harness for unit testing.
• Introduced lockfile for reproducible builds.
• Configured CI workflow to run automated tests.

Developer Tooling

• Reformatted code for consistency.
• Updated PowerShell scripts with modern packaging and approved verbs.
• Workspace configuration cleanup.

Documentation

• Updated markdownlint ignore rules.
• Improved project documentation for clarity.