Add Opera browser support with profile handling

[iamlopes-eng]

This PR adds Opera browser support to the existing numeric profile selection system.

Changes

• Added Opera browser support with consistent profile structure across all supported browsers
• Opera now supports numeric profile selection: opera://bookmarks/1, opera://bookmarks/2 instead of requiring full

Screenshots:

[Copilot]

Pull Request Overview

This PR adds Opera browser support to the existing browser bookmarks cataloging system, enabling Opera to use the same numeric profile selection pattern as other supported browsers.

• Adds Opera as a new browser variant with proper URL prefix and platform-specific data paths
• Integrates Opera into the browser configuration mapping system
• Updates documentation with Opera usage examples across all platforms

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/browsers.rs	Adds Opera enum variant, string mapping, and platform-specific user data paths
README.md	Updates documentation with Opera usage examples for all operating systems

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