Tasks

• [x] Audit existing notification and scan-result behavior; specify scope and verification.
• [x] Add regression tests and confirm failures.
• [x] Persist site details and add shared filtering with migration verification.
• [x] Implement default summary alerts and configurable direct delivery.
• [x] Enrich/filter scan API and counts; regenerate types.
• [x] Build searchable compact results with consecutive stays and booking actions.
• [x] Verify tests, lint, types and mobile/desktop visuals.
• [x] Update architecture, configuration and global checklist documentation.

Grouped results refinement

• [x] Preview and review compact date-group layouts before app integration.
• [x] Add and run regressions for grouping, filtering, sorting, collapsing, and campground links.
• [x] Integrate date sections, compact campsite rows and a full-campground provider link.
• [x] Verify frontend quality gates and actual-page desktop/mobile screenshots.
• [x] Update frontend architecture notes and global checklist.
• [x] Give the native sort select explicit sizing, appearance and an SVG chevron to avoid macOS-version differences in snapshots; refresh the affected scan-detail baselines.