Improve the Data panel's data display with monospaced text and copyable number values

[Keavon]

Broken out from #4010.

[gemini-code-assist]

Code Review

This pull request introduces several UI and layout improvements, including a new monospace option for text inputs, enhanced tooltips for menu entries, and a truncation utility for breadcrumb labels. It also addresses Safari-specific selection rendering issues and adjusts the data panel to use specialized input widgets. Feedback was provided regarding potential precision loss when displaying 64-bit integers as floats and the use of asynchronous ticks in layout calculations which might cause flickering.

[cubic-dev-ai]

2 issues found across 10 files

Confidence score: 3/5

• There is a concrete user-impacting risk in editor/src/messages/portfolio/document/data_panel/data_panel_message_handler.rs: casting u64 to f64 can lose precision for large values, which can silently display incorrect numbers in the UI.
• The issue in frontend/src/components/widgets/buttons/BreadcrumbTrailButtons.svelte is minor (off-by-one truncation with ellipsis), so it is unlikely to block merge on its own.
• Given the high-severity, high-confidence precision bug, this carries some regression risk until addressed, even though the second issue is low impact.
• Pay close attention to editor/src/messages/portfolio/document/data_panel/data_panel_message_handler.rs and frontend/src/components/widgets/buttons/BreadcrumbTrailButtons.svelte - numeric precision in UI rendering and truncation boundary behavior.

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="frontend/src/components/widgets/buttons/BreadcrumbTrailButtons.svelte">

<violation number="1" location="frontend/src/components/widgets/buttons/BreadcrumbTrailButtons.svelte:29">
P2: The truncation adds an ellipsis without reserving space for it, causing output to exceed the 40-character limit by one character.</violation>
</file>

<file name="editor/src/messages/portfolio/document/data_panel/data_panel_message_handler.rs">

<violation number="1" location="editor/src/messages/portfolio/document/data_panel/data_panel_message_handler.rs:600">
P1: Casting `u64` to `f64` can silently corrupt large integer values in the UI.</violation>
</file>

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