Summary

• sync develop into main
• polish desktop and mobile web styling, settings chrome, and mobile terminal surfaces
• fix the mobile settings config editor fill-height layout regression

Test Plan

• pnpm --filter @coder-studio/web exec vitest run src/features/settings/components/settings-page.test.tsx -t "shows provider base settings first on mobile and enters config files through the secondary action|uses a scrollable mobile detail layout for secondary settings pages without fill-height classes"
• pnpm --filter @coder-studio/web exec vitest run src/features/settings/components/config-editor.test.tsx -t "preserves the full config path|shows save status in the footer|renders text-bearing actions|preserves the bounded missing-file empty-state copy"
• pnpm --filter @coder-studio/web exec vitest run src/styles/components.theme.test.ts -t "keeps settings navigation aligned with desktop editor chrome on both desktop and mobile|keeps provider config editing closer to embedded editor panes than modal-like cards"