Add Review statistics and aggregate sequence timelines

[mattdawkins]

Add Statistics between Datasets and Results in Review on desktop and web. Opening it loads queued selections and summarizes all loaded sequences using each sequence’s saved confidence thresholds, independently of the Results query.

Category and attribute counts are searchable, sortable, and paginated. Attribute values are split by track/detection scope, including false and zero. Counts update after edits, deletion, reload, and selection changes; partial loads are labelled.

Virtualized timeline rows show one plot per sequence, combining all cameras. Colored per-type step areas use a shared count scale and horizontal plateaus like the annotation count timelines. Matching track IDs are unioned across cameras to avoid counting overlapping views twice. Camera FPS values align elapsed-time ranges; if any FPS is unknown, the row uses frames. Rows sort newest capture time first, followed by undated sequences. Existing annotation timeline components and behavior are unchanged.

Count tables retain per-camera annotation counts, with each track counted once per qualifying category. Video timeline extents are labelled when only the annotated range is known. Fixed-size bins and simplified step paths bound plotting work; sequence links and Statistics session restoration are included.

Validation: 98 review tests pass, including camera grouping through the review service, overlapping camera IDs, differing FPS, gaps, step geometry, saved thresholds, attribute scope/values, chronological order, a 1,000-sequence case, edits, queued loading, and session restoration. ESLint and TypeScript pass. The combined viame/main changes passed 298 tests and desktop/web production builds. An Electron rendering check confirmed one row for a two-camera sequence, per-type step geometry, parent-name date sorting, and readable table contrast.