Update MUI to v9.0.1

[Copilot]

Upgrades @mui/material, @mui/system, and @mui/styled-engine-sc from v6.1.8 to v9.0.1, fixing all resulting breaking changes.

Package changes

• Bumped all three MUI packages to 9.0.1 across dependencies, devDependencies, and peerDependencies
• Added lodash as an explicit dependency — MUI v9 dropped it from its own deps, but rusticTheme.ts imports it directly
• Added overrides to coerce uniforms-mui@4.0.0 (which declares @mui/material: ^6.0.0) to accept v9, and pinned react-is to ^18.3.1 to avoid type conflicts with MUI v9's internal use of react-is@19

Breaking changes fixed

Tooltip.PopperProps removed (commonControls.tsx, mediaIconButton.tsx)

// before
<Tooltip PopperProps={{ container: el }}>
// after
<Tooltip slotProps={{ popper: { container: el } }}>

CSS system props removed from Stack/Box — alignItems, justifyContent, textAlign, mt, display, gap no longer accepted as direct props; must use sx (messageCanvas.tsx, pdfViewer.tsx, weather.tsx, vegaLiteViz.tsx)

// before
<Stack alignItems="center" direction="row">
// after
<Stack sx={{ alignItems: 'center' }} direction="row">

Button variant-color styleOverrides keys removed (rusticTheme.ts) — containedPrimary, containedSecondary, outlinedSecondary, textSecondary no longer valid as top-level override keys; merged into root via CSS class selectors

// before
MuiButton: { styleOverrides: { containedPrimary: { ... } } }
// after
MuiButton: { styleOverrides: { root: { '&.MuiButton-containedPrimary': { ... } } } }

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• download.cypress.io
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node node index.js --exec install (dns block)
• mui.com
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)