feat: Run Comparison Improvements

[camielvs]

Description

Third PR in the run-comparison stack. A batch of improvements that make the comparison more useful and detailed.

What's new:

• Run metadata comparison — a section at the top of the Compare page showing differences in run-level info (author, created time, run arguments, annotations), with a count of how many things changed.
• Artifact comparison — from a task's detail you can now open a side-by-side view of that task's output artifacts across both runs.
• Cache awareness — tasks now surface whether caching was enabled/disabled and flag it as a change when it differs between runs.
• Change summaries — graph nodes show a short human-readable caption of what changed (e.g. "component · 2 arguments · cache disabled").
• Better log comparison — the log dialog now uses a proper side-by-side diff editor instead of two stacked log panes.
• Share button — copies a link to the current comparison to your clipboard.
• Also filters out editor-only annotations (positions, z-index, etc.) so cosmetic changes don't show up as real diffs.

Type of Change

• New feature
• Improvement

[github-actions]

🎩 Preview

A preview build has been created at: 07-14-feat_run_comparison_improvements/d12b01c

[camielvs]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• feat: Run Comparison Improvements #2526 👈 (View in Graphite)
• feat: Run Comparison - Graph View #2519
• feat: Explore Run Comparison Tool #2511
• master

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[camielvs]

Closing in favour of a more decentralized PR stack. See #2596