fix: [M3-7260] - Managed Summary layout

[hana-akamai]

Description 📝

Fix loading and dark mode styling for the Managed Summary tab

Preview 📷

Before	After
before.mov	after.mov

How to test 🧪

Prerequisites

(How to setup test environment)

• Have an account that's Managed (you can do so via admin)

Reproduction steps

(How to reproduce the issue, if applicable)

• On another branch, go to /managed/summary and observe the styling loading blip
• The container background in dark mode does not match the graph.

Verification steps

(How to verify changes)

• Go to /managed/summary, there should no longer be a styling loading blip.
• The container background in dark mode should now match the graph.

As an Author I have considered 🤔

Check all that apply

• 👀 Doing a self review
• ❔ Our contribution guidelines
• 🤏 Splitting feature into small PRs
• ➕ Adding a changeset
• 🧪 Providing/Improving test coverage
• 🔐 Removing all sensitive information from the code and PR description
• 🚩 Using a feature flag to protect the release
• 👣 Providing comprehensive reproduction steps
• 📑 Providing or updating our documentation
• 🕛 Scheduling a pair reviewing session
• 📱 Providing mobile support
• ♿ Providing accessibility support

[github-actions]

Coverage Report: ✅
Base Coverage: 79.86%
Current Coverage: 79.86%

[mjac0bs]

This was one of those things that drove me a little nuts every time I saw it -- thanks for fixing!

Screen.Recording.2024-01-08.at.2.18.08.PM.mov

[bnussman-akamai]

Looks much better!