[JFWooten4]

Problem

At compact horizontal widths (such as the attached ~500px viewer screenshot), the PDF search field stops too far before the Sweetie Bot Summarize with ChatGPT button. The second toolbar row leaves an unnecessary blank gap between them, making the controls appear misplaced.

Changes

• Replace the narrow second-row search group's fixed calc(100% - 88px) width with right: 46px; width: auto, allowing it to stretch up to the adjacent button.
• Keep the existing 8px left/right insets, 30px Sweetie Bot action, and 8px spacing between the search field and Sweetie Bot without altering the desktop/one-row layout or click handlers.
• Add an automated regression assertion in tests/printed-page-jump.test.mjs for the two-row breakpoint and toolbar geometry at 320, 500, 720, and 900 CSS pixels.

Verification

• Compared against main: 2 commits ahead, 0 behind. Only src/viewer/navigation/toolbar-layout.css and tests/printed-page-jump.test.mjs changed.
• Checked the committed CSS and test content and verified the inferred spacing is exactly 8px for the specified compact widths.
• Not run: full Node test suite or real Chromium extension rendering. Verify the screenshot's ~500px width, nearby narrow widths, wider single-row behavior, and both themes with the extension loaded.

Related changes

• #39 placed the ChatGPT action directly beside the search field.
• #47 introduced Sweetie Bot and Pinkie's mirror iconography.
• #135 fixed earlier narrow-view two-row layout regressions.