Add copy link button to card browser (closes #2937)

[Adarshkumar0509]

Description

The card browser on cornucopia.owasp.org was missing a copy link button. I added a small rectangular copy button that sits right under the card, above the "How to play?" link. Clicking it copies the card URL (/cards/{card_id}) to the clipboard. It also has a fallback for older browsers that don't support the Clipboard API.

fixed issue: #2937

Screenshots

before:-

After:-

copy card link is working perfectly also i verified that locally as well

AI Tool Disclosure

• My contribution does not include any AI-generated content
• My contribution includes AI-generated content, as disclosed below:
  • AI Tools: [e.g. GitHub CoPilot, ChatGPT, JetBrains Junie etc.]
  • LLMs and versions: [e.g. GPT-4.1, Claude Haiku 4.5, Gemini 2.5 Pro etc.]
  • Prompts: [Summarize the key prompts or instructions given to the AI tools]

Affirmation

• My code follows the CONTRIBUTING.md guidelines

[Adarshkumar0509]

hii @sydseter please take a look at this whenever you have time.