H-5768: Extract styles from all component files in Petrinaut

[kube]

🌟 What is the purpose of this PR?

Modernizes styling by extracting inline styles into css/cva utilities across the editor to improve consistency, reuse, and theming.

• Converts all components to class-based styles
• Adds style variants (e.g., isSelected, isDisabled, isReadOnly) and consolidates repeated patterns (spacing, borders, z-index, hover/focus states)
• Minor UI polish (layout, paddings, shadows); no functional or API changes intended

Pre-Merge Checklist 🚀

🚢 Has this modified a publishable library?

This PR:

• modifies an npm-publishable library and I have added a changeset file(s)

📜 Does this require a change to the docs?

The changes in this PR:

• are internal and do not require a docs change

🕸️ Does this require a change to the Turbo Graph?

The changes in this PR:

• do not affect the execution graph

🐾 Next steps

• Continue refactoring by progressively cleaning styles, and find a common way to organize them.
• Adapt/Migrate UI to match Figma mockups

❓ How to test this?

Use latest Petrinaut deployment

[kube]

• H-5764: Setup Sentry UserFeedback + ErrorTracker #8241
• H-5691: Simulation Timeline Visualizer #8211
• H-5884: Add Panel SubView, with Horizontal and Vertical SubViews containers #8209
• H-5768: Extract styles from all component files in Petrinaut #8205 👈 (View in Graphite)
• H-5768: Quick Simulation in Edit Mode, and disable Simulate temporarily #8195
• H-5850: Fix PandaCSS and single vite.config #8194
• H-5840: SDCPN diagnostics panel with global type-checker #8171
• main

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[cursor]

PR Summary

Modernizes styling by moving inline styles to css/cva utilities and adding state-based variants for consistency and reuse.

• Refactors UI components (menu, tooltip, segment-group, color-select) to use class-based styles and cva variants
• Converts major editor surfaces to extracted styles: Left Sidebar sections (nodes-section, types-section, differential-equations-section, hamburger-menu, floating-title), Bottom Panel (bottom-panel, diagnostics-content, parameters-content), Properties Panel (place-properties, transition-properties, type-properties, differential-equation-properties, initial-state-editor, multiple-selection, sortable-arc-item, visualizer-error-boundary, properties-panel)
• Updates editor-view layout and SDCPN/arc rendering to class-based styling
• Introduces common variants (e.g., isSelected, isDisabled, isReadOnly) and shared spacing/border/shadow tokens; removes inline style duplication
• Adds a changeset for @hashintel/petrinaut (patch)

^{Written by Cursor Bugbot for commit 5a8bb42. This will update automatically on new commits. Configure here.}

[CiaranMn]

We can probably keep this kind of thing out of the changelog unless it has some impact on consumers (e.g. improves performance, changes interface, changes features, changes appearance). i.e. we can delete this file.

Each of these becomes a line in the changelog and each line should matter to someone who isn't us.

[kube]

Ok I remove it.