fix(ui): keep image annotation save action visible

[katya4oyu]

Problem

On narrow screens, the image annotation toolbar extends beyond the visible area, making the Save button unreachable.

Change

• Limit the toolbar to the visible viewport width, including mobile safe areas.
• Keep the existing controls through Clear in one row and make them horizontally scrollable when they do not fit.
• Keep the separator and Save button fixed at the right edge.
• Preserve the existing control order, colors, sizes, and content-sized layout on wider screens.

Verification

• bun test packages/ui/components/ImageAnnotator
• DOM_TESTS=1 bun test --isolate packages/ui/components/ImageAnnotator/ImageAnnotator.layout.test.tsx packages/ui/components/ImageAnnotator/ImageAnnotator.shortcuts.test.tsx
• bun run --cwd packages/ui typecheck
• bun test packages/ui (784 pass, 574 DOM-gated skips, 0 fail)
• bun run build:review
• bun run build:hook
• git diff --check
• Verified on physical Mobile Safari that the toolbar is not clipped and Save remains usable.

[backnotprop]

Merged, thanks @katya4oyu. The switch to the existing safe-area overlay class makes the image annotator consistent with the dialogs and composer, and the canvas cap keeps the image clear of the new padding at every width. Ships in the next release.

[katya4oyu]

thanks!