[JFWooten4]

Summary

Fix two PDF viewer layout regressions visible on narrow desktop windows:

1. Footerless documents: The minimap's bottom controls sat 48px above the bottom edge even when no footnotes or footnote scrubber were present. Apply the split-pane clearance only when #document-scrubber is not hidden; the existing scrubber-height offset is preserved when footnotes are present.
2. Collapsed minimap: The reopen button was shifted into the native scrollbar gutter by right: calc(100% - 100vw), clipping its right edge and control glyph. Anchor the button within the layout viewport, add its missing perimeter border, and retain the left-side placement override.

Regression coverage

• Update the split-pane CSS assertion to require the clearance to be conditional on a visible footnote scrubber.
• Assert the collapsed button stays outside the scrollbar, has a complete border, and still works when navigation is on the left.
• Existing document-scrubber regression checks already verify that PDFs with no footnotes leave the scrubber hidden and reserve no scrubber height.

Verification

• Verified the candidate Git tree differs from main and contains exactly two modified files: src/viewer/navigation/minimap.css and tests/minimap.test.mjs.
• Confirmed the branch is one commit ahead, zero behind main; validated the CSS selectors and intended assertions against the proposed content.
• Not run: the Node test suite and manual in-browser visual checks (no local repository/network checkout available in this session). Verify a one-page PDF without footnotes, a PDF with footnotes, and the collapsed/re-expanded minimap both on the right and left.

Related changes

• #190 originally introduced the split-view bottom clearance.
• #193 updated regression expectations for that clearance.
• #180 aligned the native scrollbar with the viewer toolbar.