fix: avoid browser tabs content scripts memory leak

[ACTCD]

fix #863

[Copilot]

Pull Request Overview

This PR fixes a memory leak issue in browser tab content scripts by properly managing event listeners and preventing accumulation of orphaned listeners when tabs become hidden or inactive.

• Adds proper cleanup for runtime message listeners using visibility state tracking
• Implements the { once: true } option for one-time event listeners
• Manually removes event listeners for document state changes to prevent accumulation

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/ext/content-scripts/entry-userscripts.js	Adds memory leak prevention through proper event listener cleanup and once-only DOM events
src/ext/content-scripts/entry-script-market.js	Implements visibility-based listener management and removes unnecessary variable reset

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