Fix map view: hover-to-list highlighting, pagination clarity, and marker style

[ewlarson]

Summary

This PR completes the search map interaction work and folds the subsequent review fixes into one coherent experience. It synchronizes map pins with result cards, makes overlapping points predictable, keeps the results map visible while the full page remains scrollable, and standardizes compact pagination across Map, List, and Gallery views.

User-facing changes

Map and result interaction

• Replaces circular centroid markers with numbered map pins whose labels stay upright.
• Highlights the matching result card when a distinct map pin is hovered or selected.
• Scrolls an offscreen result into view when its pin is hovered, without moving the sticky map out of context.
• Keeps highlighted card borders fully visible and prevents hover-driven scroll feedback from jumping the page backward or forward.
• Keeps marker selection and highlighting stable without rebuilding markers beneath the pointer.
• Shows the hovered result geometry without panning or zooming the map.

Overlapping points

• Keeps collapsed overlapping markers inert on hover so they do not highlight or scroll to an arbitrary result.
• Identifies collapsed overlaps with a zoom-in cursor and a click-to-separate title.
• Enables hover, selection, and result scrolling only after the markers have spiderfied into distinct points.
• Preserves the spiderfied layout while moving between its markers, avoiding the jarring repositioning and collapse seen during review.

Page layout and scrolling

• Makes the right-hand results map sticky near the top of the viewport.
• Lets all results participate in normal page flow instead of truncating the results column inside an internal scroller.
• Removes the results-column scrollbar and scroll trap so users can reach both the first result and the footer naturally.
• Prevents List cards from exceeding their grid column, eliminating document-level horizontal scrolling.

Pagination and map context

• Moves the current-page map note onto the results map so it cannot be confused with the Location facet map.
• Uses the final note text: “This map only renders the current page of search results. Use pagination to review other matches.”
• Adds the compact « Previous | 1 - 20 of 12,766 | Next » control beside the results summary.
• Uses the same compact pagination in Map, List, and Gallery views and removes the older numbered pager from the bottom of List and Gallery.
• Keeps result ranges and absolute pin/result numbering accurate across pages.
• Suppresses misleading zero-result copy while a search is still loading.

Implementation notes

• Extends map context state so hover source, hovered resource, geometry, and selected marker stay synchronized.
• Keeps the OverlappingMarkerSpiderfier lifecycle stable and updates marker color and stacking without replacing marker DOM.
• Adds semantic current-item state to highlighted results and limits automatic scrolling to map-originated hover interactions.
• Adds responsive minimum-width constraints through the results grid and List cards instead of hiding overflow at the page level.

Testing

• Full frontend suite: 80 test files, 996 tests passed.
• Production frontend build passed.
• Focused regression coverage includes numbered pins, marker selection, stable spiderfying, collapsed-overlap behavior, result highlighting and scrolling, sticky page flow, pagination in all three views, loading states, and List width constraints.
• Targeted ESLint and Prettier checks passed for the changed search components and tests.
• Interactive browser checks covered page transitions, sticky-map scrolling, footer access, overlapping markers, and horizontal overflow in Map, List, and Gallery views.

Issue links

Closes #269
Closes #373
Closes #150