Feature Request: Developer-Centric Enhancements (Sensitive Data Masking)

For all's convenience, please use English to fill this issue.

Is your feature request related to a problem? Please describe.

As a developer, I frequently use QuickLook to glance at configuration files. I currently face two main points of friction:

Visualizing Styles: It is difficult to verify colors in CSS or Tailwind configs without opening a full IDE, as hex codes and RGBA strings aren't intuitive at a glance.

Security Risks: Previewing .env files during screen shares or presentations is dangerous, as sensitive API keys and secrets are immediately exposed in plain text.

Describe the solution you'd like

I would like to propose a "Developer Power-User" update to the text previewer that includes:

1. Live Color Swatches: Automatically detect color strings (Hex, RGB, RGBA, HSL) in CSS, SCSS, and Tailwind config files and render a small color preview box next to the code.

2. Environment Variable Masking: For .env files, implement a "Privacy Mode" that masks values (e.g., DATABASE_URL=********). A "Show/Hide" toggle (eye icon) could be added to the toolbar to reveal the secrets when needed.

Describe alternatives you've considered

For Colors: Relying on memory or opening VS Code just to check a shade.

For Masking: Avoiding .env files entirely during calls or manually blurring screen recordings.

No files or tests are identified. Start by locating the text previewer and toolbar entry points, then separate the color-rendering and .env privacy requirements. Done means both requested behaviors work without exposing masked values and are covered by the project's tests.