[SPARK-56048][UI] Add copy plan text and share link buttons to SQL execution page

[yaooqinn]

What changes were proposed in this pull request?

Add two buttons next to the existing Download button on the SQL execution detail page:

• 📋 Copy Plan — copies the physical plan text to clipboard
• 🔗 Copy Link — copies the current page URL to clipboard

Both use navigator.clipboard.writeText and show a toast notification on success.

Why are the changes needed?

When debugging query performance, users frequently need to share the physical plan or page link via Slack/JIRA/email. Currently they must manually select text or copy the URL bar. One-click buttons improve this workflow.

Does this PR introduce any user-facing change?

Yes — two new buttons on the SQL execution detail page.

How was this patch tested?

Compilation verified. Manual testing.

Was this patch authored or co-authored using generative AI tooling?

Yes, Generated-by: GitHub Copilot(claude-opus-4.6-1m).

[dongjoon-hyun]

+1, LGTM. Thank you, @yaooqinn .

[dongjoon-hyun]

ditto

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BTW, are you going to use your personal message instead of complying the Apache Spark Pull Request template, @yaooqinn ?

I'm not sure why the Copilot ignores the pull request template, but when I ask Cluade Caude to write a PR description based on the pull request template (here, I used the file reference feature of Claude Claude), Claude Code works well by respecting the Apache Spark Pull Request template like the following. In these days, it's rare to write the PR description from the scratches. I assume that you are also taking advantage of Copilot for your PR description writing.

spark/.github/PULL_REQUEST_TEMPLATE

Lines 55 to 56 in ca60558

	If generative AI tooling has been used in the process of authoring this patch, please include the
	phrase: 'Generated-by: ' followed by the name of the tool and its version.

[yaooqinn]

Merged to master, thank you @dongjoon-hyun